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Subject: alt.video.dvd Frequently Asked Questions (FAQ)
This article was archived around: 19 Mar 1998 12:13:53 GMT
Last-modified: Jan 13, 1998
Maintainer: Jim Taylor <firstname.lastname@example.org>
DVD Frequently Asked Questions (with answers!)
This is the 9-Feb-98 revision of the FAQ for the alt.video.dvd Usenet
newsgroup. (See below for what's new.)
Please send corrections, additions, and new questions to Jim Taylor
Where can I get this FAQ?
* It is posted periodically as "alt.video.dvd Frequently Asked Questions
(FAQ)" to alt.video.dvd, news.answers, alt.answers, and other relevant
* The most current version is on the Web at
* Mirror copies are at
<http://www.dvdresource.com/resourceindex.shtml>, and other places.
* A Spanish translation is available at
Muchisimas gracias to Modesto Garrido for the translation.
* A text archive of the version last posted to newsgroups is at
<http://www.faqs.org/faqs/rec-video/dvd-faq> and other FAQ mirrors. You
can have a text version of the FAQ emailed to you by sending email to
Recent significant changes (last posted to newsgroups on Jan 12):
* 98-02-09: There's now a Spanish translation of this FAQ. (Thanks,
* 98-02-05: More DVD authoring systems. (5.2)
* 98-01-22: Link to Eric's drive info page. (1.5)
* 98-01-20: MultiRead and Type II updates for CD-R compatibility. (2.43)
* 98-01-18: New question: [1.28] The disc says Dolby Digital. Why do I
get 2-channel surround audio?
* 98-01-18: Pointer to rental locations database. (1.15)
* 98-01-18: Pointer to Chris' title list. (1.6)
* 98-01-18: Reality check and a few new predictions. (1.9)
* 98-01-13: Links to DVD primers from Nimbus and Sonic. (6.3)
* 98-01-13: Explained THX (Thanks, Wayne). Added a few more audio format
*  General DVD
* [1.1] What is DVD?
* [1.2] What are the features of DVD-Video?
* [1.3] What's the quality of DVD-Video? Why do some demos look so
* [1.4] What are the disadvantages of DVD?
* [1.5] What DVD players and drives are available?
* [1.6] What DVD titles are available?
* [1.7] How much do players and drives cost?
* [1.8] How much do discs cost?
* [1.9] How quickly will DVD become established?
* [1.10] What are "regional codes," "country codes," or "zone
* [1.11] What are the copy protection issues?
* [1.12] What about DVD-Audio or Music DVD?
* [1.13] Which studios are supporting DVD?
* [1.14] Can DVD record from VCR/TV/etc?
* [1.15] What happens if I scratch the disc? Aren't discs too
fragile to be rented?
* [1.16] VHS is good enough, why should I care about DVD?
* [1.17] Is the packaging different from CD?
* [1.18] What's a dual-layer disc? Will it work in all players?
* [1.19] Is DVD-Video a worldwide standard? Does it work with NTSC,
PAL and SECAM?
* [1.20] What about animation on DVD? Doesn't it compress poorly?
* [1.21] Why do some discs require side flipping? Can't DVDs hold
four hours per side?
* [1.22] Why is the picture squished, making things look too skinny?
* [1.23] Do all videos use Dolby Digital (AC-3)? Do they all have
* [1.24] Can DVDs have laser rot?
* [1.25] Which titles are pan & scan only? Why?
* [1.26] How do I make the subtitles on my Pioneer player go away?
* [1.27] What is a layer change? Where is it on specific discs?
* [1.28] The disc says Dolby Digital. Why do I get 2-channel
*  DVD's relationship to other products
* [2.1] Will DVD replace VCRs?
* [2.2] Will DVD replace CD-ROM?
* [2.3] Can CD-R writers create DVDs?
* [2.4] Is CD compatible with DVD?
* [2.4.1] Is CD audio (CD-DA) compatible with DVD?
* [2.4.2] Is CD-ROM compatible with DVD-ROM?
* [2.4.3] Is CD-R compatible with DVD-ROM?
* [2.4.4] Is CD-RW compatible with DVD?
* [2.4.5] Is Video CD compatible with DVD?
* [2.4.6] Is Photo CD compatible with DVD?
* [2.4.7] Is CD-i compatible with DVD?
* [2.4.8] Is Enhanced CD compatible with DVD?
* [2.4.9] Is CD+G compatible with DVD?
* [2.4.10] Is CDV compatible with DVD?
* [2.4.11] Is MP3 compatible with DVD?
* [2.5] Is laserdisc compatible with DVD?
* [2.6] Will DVD replace laserdisc? Should I buy laserdisc now or
wait for DVD and HDTV?
* [2.7] How does DVD compare to laserdisc?
* [2.8] Can I modify or upgrade my laserdisc player to play DVD?
* [2.9] Does DVD support HDTV (DTV/ATV)? Will HDTV make DVD
* [2.10] What's Divx?
*  DVD technical details
* [3.1] What are the outputs of a DVD player?
* [3.2] How do I hook up a DVD player?
* [3.3] What are the sizes and capacities of DVD?
* [3.4] What are the video details?
* [3.5] How do the aspect ratios work?
* [3.6] What are the audio details?
* [3.7] How do the interactive features work?
*  DVD and computers
* [4.1] Can I play DVD movies on my computer?
* [4.2] What are the features and speeds of DVD-ROM drives?
* [4.3] What about recordable DVD: DVD-R, DVD-RAM, DVD+RW, and
*  DVD production
* [5.1] How much does it cost to produce a DVD? Isn't DVD much more
expensive than videotape, laserdisc, and CD-ROM?
* [5.2] What DVD authoring systems are available and how much do
* [5.3] Who can produce a DVD for me?
* [5.4] Who can test or verify DVDs?
*  Miscellaneous
* [6.1] Who invented DVD and who owns it? Whom to contact for
specifications and licensing?
* [6.2] Who is making or supporting DVD products?
* [6.3] Where can I get more information about DVD?
*  Leftovers
* [7.1] Unanswered questions
* [7.2] Notation and units
* [7.3] Acknowledgments
 General DVD
[1.1] What is DVD?
DVD, which stands for Digital Video Disc, Digital Versatile Disc, or
nothing, depending on whom you ask, is the next generation of optical disc
storage technology. It's essentially a bigger, faster CD that can hold video
as well as audio and computer data. DVD aims to encompass home
entertainment, computers, and business information with a single digital
format, eventually replacing audio CD, videotape, laserdisc, CD-ROM, and
perhaps even video game cartridges. DVD has widespread support from all
major electronics companies, all major computer hardware companies, and
about half of the major movie and music studios, which is unprecedented and
says much for its chances of success (or, pessimistically, the likelihood of
it being forced down our throats).
It's important to understand the difference between DVD-Video and DVD-ROM.
DVD-Video (often simply called DVD) holds video programs and is played in a
DVD player hooked up to a TV. DVD-ROM holds computer data and is read by a
DVD-ROM drive hooked up to a computer. The difference is similar to that
between Audio CD and CD-ROM. DVD-ROM also includes future variations that
are recordable one time (DVD-R) or many times (DVD-RAM). Most people expect
DVD-ROM to be initially much more successful than DVD-Video. Most new
computers with DVD-ROM drives can also play DVD-Videos (see 6.1).
There's also a DVD-Audio format. The technical specifications for DVD-Audio
are not yet determined.
[1.2] What are the features of DVD-Video?
* Over 2 hours of high-quality digital video (over 8 on a double-sided,
* Support for widescreen movies on standard or widescreen TVs (4:3 and
16:9 aspect ratios).
* Up to 8 tracks of digital audio (for multiple languages), each with as
many as 8 channels.
* Up to 32 subtitle/karaoke tracks.
* Automatic "seamless" branching of video (for multiple story lines or
ratings on one disc).
* Up to 9 camera angles (different viewpoints can be selected during
* Menus and simple interactive features (for games, quizzes, etc.).
* Multilingual identifying text for title name, album name, song name,
cast, crew, etc.
* "Instant" rewind and fast forward, including search to title, chapter,
track, and timecode.
* Doubles as a frisbee if the movie sucks.
* Durability (no wear from playing, only from physical damage).
* Not susceptible to magnetic fields. Resistant to heat.
* Compact size (easy to handle, store, and ship; players can be portable;
replication is cheaper).
Note: Most discs do not contain all features (multiple audio/subtitle
tracks, seamless branching, parental control, etc.). Some discs may not
allow searching or skipping.
Most players support a standard set of features:
* Language choice (for automatic selection of video scenes, audio tracks,
subtitle tracks, and menus).*
* Special effects playback: freeze, step, slow, fast, and scan (no
reverse play or reverse step).
* Parental lock (for denying playback of discs or scenes with
* Programmability (playback of selected sections in a desired sequence).
* Random play and repeat play.
* Digital audio output (PCM stereo and Dolby-Digital).
* Compatibility with audio CDs.
* Must be supported by additional content on the disc.
Some players include additional features:
* Component (YUV or RGB) output for highest-quality picture.
* Compatibility with Video CDs.
* Six-channel analog output from internal audio decoder.
* Compatiblity with laserdiscs and CDVs.
* Reverse single frame stepping.
* RF output (for TVs with no direct video input).
* Multilingual on-screen display.
[1.3] What's the quality of DVD-Video? Why do some demos look so bad?
DVD has the capability to produce near-studio-quality video and
better-than-CD-quality audio. DVD is vastly superior to videotape and
generally better than laserdisc (see 2.8.). However, quality depends on many
production factors. Until compression experience and technology improves we
will occasionally see DVDs that are inferior to laserdiscs. Also, since
large amounts of video have already been encoded for Video CD using MPEG-1,
a few low-budget DVDs will use that format (which is no better than VHS)
instead of higher-quality MPEG-2.
DVD video is compressed from digital studio master tapes to MPEG-2 format.
This "lossy" compression removes redundant information (such as areas of the
picture that don't change) and information that's not readily perceptible by
the human eye. The resulting video, especially when it is complex or
changing quickly, may sometimes contain "artifacts" such as blockiness,
fuzziness, and video noise depending on the processing quality and amount of
compression. At average rates of 3.5 Mbps (million bits/second), compression
artifacts may be occasionally noticeable. Higher data rates can result in
higher quality, with almost no perceptible difference from the original
master at rates above 6 Mbps. As MPEG compression technology improves,
better quality is being achieved at lower rates.
Video from DVD sometimes contains visible artifacts such as color banding,
blurriness, blockiness, fuzzy dots, shimmering, missing detail, and even
effects such as a face which "floats" behind the rest of the moving picture.
It's important to understand that the term "artifact" refers to anything
that was not originally present in the picture. Artifacts are sometimes
caused by poor MPEG encoding, but artifacts are more often caused by a
poorly adjusted TV, bad cables, electrical interference, sloppy digital
noise reduction or picture enhancement, poor film-to-video transfer, film
grain, player faults, disc read errors, etc. Most DVDs have few or no
visible MPEG compression artifacts. If you think otherwise, you are
misinterpreting what you see.
Some early DVD demos were not very good, but this is not an indication that
DVD quality is bad, since other demos show no artifacts or other problems.
Bad demos are simply an indication of how bad DVD can be if not properly
processed and correctly reproduced. Many demo discs were rushed through the
encoding process in order to be distributed as quickly as possible. Contrary
to common opinion, and as stupid as it may seem, these demos are not
carefully "tweaked" to show DVD at its best. In-store demos should be viewed
with a grain of salt, since most salespeople are incapable of properly
adjusting a television set. Most TVs have the sharpness set too high for the
clarity of DVD. This exaggerates high-frequency video and causes distortion,
just as the treble control set too high for a CD causes it to sound harsh.
Many DVD players output video with a black-level setup of 0 IRE (Japanese
standard) rather than 7.5 IRE (US standard). On TVs that are not properly
adjusted this can cause some blotchiness in dark scenes. DVD video has
exceptional color fidelity, so muddy or washed-out colors are almost always
a problem in the display, not in the DVD player or disc.
DVD audio quality is excellent. One of DVD's audio formats is LPCM (linear
pulse code modulation) with sampling sizes and rates higher than audio CD.
Alternatively, audio for most movies is stored as discrete multi-channel
surround sound using Dolby Digital audio compression similar to the surround
sound formats used in theaters. As with video, audio quality depends on how
well the processing and encoding was done. In spite of compression, Dolby
Digital is close to CD quality.
The final assessment of DVD quality is in the hands of consumers. Most
viewers consistently rate it better than laserdisc, but no one can guarantee
the quality of DVD, just as no one should dismiss it based on demos or
hearsay. In the end it's a matter of individual perception.
[1.4] What are the disadvantages of DVD?
* It will take years for movies and software to become widely available.
* It can't record (yet). (See 1.14 and 4.3)
* It has built-in copy protection and regional lockout. (See 1.11 and
* It uses digital compression. Poorly compressed audio or video may be
blocky, fuzzy, harsh, or vague. (See 1.3)
* The audio downmix process for stereo/Dolby Surround can reduce dynamic
range. (See 3.6)
* It doesn't fully support HDTV. (See 2.9)
* Some DVD players and drives may not be able to read CD-Rs. (See 2.4.3)
* First-generation DVD players and drives can't read DVD-RAM discs. (See
* Current players can't play in reverse at normal speed.
[1.5] What DVD players and drives are available?
Some manufacturers originally announced that DVD players would be available
as early as the middle of 1996. These predictions were woefully optimistic.
Delivery was initially held up for "political" reasons of copy protection
demanded by movie studios, but was later delayed by lack of titles.
* Japan (Region 2)
o Panasonic: A-100, 79,800 yen; A-300, 98,000 yen (Nov 1996);
DVD-A350, 94,000 yen; DVD-K500, 110,000 yen (Nov 97); DVD-A450,
100,000 yen (Dec 10, 97). YPbPr component out, 6-ch DD, 96 kHz
o Toshiba: SD-3000, 77,000 yen (Nov 96); SD-K310, 89,000 yen (Jun
o Sanyo (Toshiba-made): (Dec 96).
o Pioneer: DV-7, 83,000 yen; DVL-9, 133,000 yen; DVD-K800, 120,000
yen; DVK-1000, 248,000 yen; DV-F21 (Dec 96)
o Hitachi (Pioneer-made): (Dec 96)
o Akai: DV-P1000, 65,000 yen (Apr 97)
o Sony: DVP-S7000, 110,000 yen (Mar 97); DVP-S3000, 79,000 yen. (?,
97). YPbPr component out.
o Victor: XV-1000, 93,000 yen (Apr 97); XV-D2000, 115,000 yen. (Dec?
97). YPbPr component out, 6-ch DD.
* Korea (Regions 3 and 5)
o Samsung (Toshiba-made): Nov 96.
o LG (Goldstar): Nov 96.
* US (Region 1)
o Pioneer: DV-500, $600; DVL-700, $1000; DVL-90, $1750 (Feb 97);
DVL-909, $1100 (LD/DVD) (Jan 98); DV-606D, $700 (24-bit 96 kHz)
o Panasonic: A-100, $600; A-300, $750 (Feb 97)
o Toshiba: SD-2006, $600; SD-3006, $750 (Mar 1997); SD-2107, $600;
SD-3107 (Aug 97).
o Denon (Matsushita + Denon audio): DVD-2000, $800 (Mar 97)
o Sony: DVP-S7000, $1000 (Apr 97); DVP-S3000 (Oct 97)
o RCA (Matsushita-made): RC5200P, $500; RC5500P, $700 (Apr 97)
o Proscan (Matsushita-made): PS8600P, $750; (same circuitry as
RCA5500P) (Apr 97)
o Mitsubishi (Toshiba-made): DD-1000, $700 (Apr 1997)
o Philips/Magnavox: DVD 400AT, $550 (May 97); 420AT, $650 (Oct 97).
o JVC: XV1000, $600 (Jun 97)
o Samsung: DVD905, $750 (Sep 97)
o Onkyo (Toshiba-made): DVD-7, $1000 (Fall 97)
o Marantz (Toshiba-made): DVD810.
o Yamaha (Matushita-made): DVD-1000 (Fall 97).
o Zenith (Toshiba-made): DVD2000 (Fall 97).
o Harman Kardon: HDV-715 (Fall 97).
* Europe (Region 2)
o Panasonic: A-100EC, 1300DM; A-300EC, 1400DM (Mar 97); A-350EC,
1500DM (6-channel MPEG-2 & DD) (Jan 98)
o Thomson (Matsushita-made): France, 4990 francs (Mar 97)
* Asia (Region 3)
o Panasonic: Feb 97.
o Pioneer: May 97
o Sony: DVP-S7000 (May 97)
* Australia (Region 4)
* Panasonic: A300; A350 (6-channel MPEG-2) (Dec 97)
* Sony: DVP-S7000
Projected player releases:
* Japan (Region 2)
o Toshiba: 2 portable players, 75,000 yen each (Nov 97).
o Philips: Spring 98.
o Panasonic: DVD-L10 portable player (Spring 98). yen).
o Pioneer: DV-S9. ("reference player")
o Toshiba SD-2100(N).
* US (Region 1)
o Akai: DV-P1000.
o Meridian: 586, $3500!.
o Faroudja (modified Toshiba 3006): No date. (DV-1000, $5500!).
o Panasonic: DVD-A110, DVD-A310, DVD-A510 (all DTS-compatible);
DVD-A350, ~$750; DVD-A450, ~$825; DVD-K500, ~$900 (Early 1998);
DVD-L10, $1300 (portable) (Spring 98).
o Kenwood: January 1998.
o Runco: SAR-200, $15,000 (200-disc changer, THX-certified) (Jan
o Denon: DVD-3000, $899 (DTS-compatible) (Apr 98).
o Pioneer: DV-505, $500 (May 98).
o Onkyo: DV-S501, $850 (Summer 98).
o JVC: XV-D2000BK (24b/96kHz).
o Fisher: DVD-60, $2,400 (60-disc DVD/DVD-ROM changer).
o Hyundai, Goldstar, Hitachi (Pioneer-made), Runco (modified
Pioneer), Sharp: No date.
o Unity Motion: No date (progressive scan!).
* Europe (Region 2)
o JVC: Summer?
o Kenwood: August in Germany (LZ-25).
o Philips: Spring 1998 (DVD 730, DM 1500; DVD 930, DM 1700).
o Hitachi, Pioneer, Sony, Toshiba: Spring 1998.
o Grundig: GDV 100 G.
* Asia (Region 3)
o Toshiba: July.
* Australia/New Zealand (Region 4)
o Panasonic: Fall.
Fujitsu supposedly released the first DVD-ROM-equipped computer on Nov. 6 in
Japan. Toshiba released a DVD-ROM-equipped computer and a DVD-ROM drive in
Japan in early 1997 (moved back from December which was moved back from
November!). DVD-ROM drives from Toshiba, Pioneer, Panasonic, Hitachi, and
Sony began appearing in sample quantities as early as January 1997, but none
were to be available before May. Creative Labs' $499 PC-DVD upgrade kit
(Matsushita drive, A/V decoder board; Warner DVD-V sampler) went on sale in
the U.S. in April for $500. Samsung drives (and PCs with drives) were
available in Korea in January. Hi-Val's $799 PC-DVD upgrade kit (Toshiba
drive, Quadrant decoder; 6 DVD-ROMS including Silent Steel, Daedalus
Encounter, and Xiphias Encyclopedia Electronica) was scheduled for May, as
was Diamond Multimedia's $599 kit. STB Systems DVD Theater Upgrade Kit was
be available in July for $699. DynaTek announced a $649 upgrade kit with 6
titles. Philips drives will be available in the 2nd quarter. LG Electronics
drives were be available in July. Toshiba's Infinia DVD-ROM-equipped PC
become available Summer 1997. Compaq and Sony DVD-PCs are delayed.
Creative's new "Encore" 2x DVD-ROM kit is available for $380. Hi-Val's
2nd-generation kit is also $380. E4's CoolDVD upgrade kit for Macintoshes is
available for $499 in February 1998.
For drive details see http://www.brouhaha.com/~eric/video/dvd/.
Note: If you buy a player or drive from outside your country (e.g., a
Japanese player for use in the US) you may not be able to play region-locked
discs on it. (See 1.10.)
[1.6] What DVD titles are available?
As with hardware, rosy predictions of hundreds of movie titles for Christmas
of 1996 failed to materialize. Only a handful of DVD titles, mostly music
videos, were available in Japan for the November 1996 launch of DVD. Actual
feature films began to appear in December. By April there were over 150
titles in Japan. Movies appeared in the US in March of 1997. Currently (Sep
1997) there are about 160 titles available in the US and over 200 more that
have been announced. Compared to other launches (CD, LD, etc.) this is a
huge number. Almost 19,000 discs were purchased in the first two weeks of
the US launch -- more than expected. InfoTech predicts over 600 titles by
the end of 1997 and more than 8,000 titles by 2000. By December 1997, over 1
million individual DVD titles were shipped.
A concerted launch of DVD hardware and software in Europe is planned for the
first quarter of 1998. Over 100 titles are expected to be available by
March, with over 250 available by the end of 1998. Time Warner's official
launch of DVD in Australia (region 4) is planned for Easter of 1998.
For a complete list of titles available in the US and Canada, see
<http://www.unik.no/~robert/hifi/dvd/film1.html>, and for titles in Japan
and Europe see <http://www.unik.no/~robert/hifi/dvd/film2.html>. Another
extensive list of US titles is at
<http://www.cybercomm.nl/~michiel/surround/dvd_list.htm>. New release lists
and announcements are also available at <http://www.laserviews.com>
Concorde Video released a PAL-format "12 Monkeys" in Germany at the end of
March. They were threatened by Philips with a lawsuit for not including a
multichannel MPEG track, but the issue is now resolved (see 3.6).
DVD-ROM software will slowly appear. Approximately 50% of CD-ROM producers
have announced intentions to develop for DVD-ROM. See 6.2 for a list. Many
initial DVD-ROM titles will only be available as part of a hardware or
software bundle until the market grows larger. IDC expects that over 13
percent of all software will be available in DVD-ROM format by the end of
1998. In one sense, DVD-ROMs are simply larger faster CD-ROMs and will
contain the same material. But DVD-ROMs can also take advantage of the
high-quality video and multi-channel audio capabilities being added to many
The first DVD-ROMs will probably be "The Union Catalogue of Belgian Research
Libraries" from IVS, "PhoneDisc PowerFinder USA One" (which filled 6
CD-ROMs) from Digital Directory Assistance Inc., and "Silent Steel" from
Tsunami Media. Most early discs are bundled with hardware.
[1.7] How much do players and drives cost?
Mass-market DVD movie players currently list for $600 and up. (See 1.5 for
models and prices.) Within a few years they may approach VCR prices.
InfoTech predicts prices will be as low as $250 by the year 2000, and below
$150 by 2005.
DVD-ROM drives for computers sell for around $300 to $400. (OEM prices are
under $200.) Prices are expected to drop quickly to current CD-ROM drive
[1.8] How much do discs cost?
It varies, but most DVD movies list for $25 to $30 with street prices
between $18 and $25, even those with supplemental material. Some new
releases are initially priced for rental (near $80, the same as VHS), others
are as low as $12.
DVD-ROMs will initially be slightly more expensive than CD-ROMs since there
is more on them, they cost more to replicate, and the market is smaller. But
once production costs drop and the installed base of drives grow, DVD-ROMs
will cost about the same as CD-ROMs today.
[1.9] How quickly will DVD become established?
Not as fast as generally predicted, but faster than videotape, laserdisc,
and CD. By the end of 1997 over 500,000 DVD-Video players shipped worldwide.
349,482 of these were in the US (with about 200,000 actually sold into
homes). About ?? video titles were available worldwide, with ?? million
copies shipped. About 600 video titles were available in the US, with over 5
(?) million copies shipped and about 2 million sold. Around 330,000 DVD-ROM
drives were shipped worldwide with about 1 million bundled DVD-ROM titles.
Only 60 DVD-ROM titles were available by the end of 1997. Here are some
* Toshiba (1996): 100,000 to 150,000 DVD-Video players will be sold in
Japan between Nov. 1 and Dec. 31, 1996, and 750,000-1 million by Nov.
1, 1997. (Actual count of combined shipments by Matsushita, Pioneer,
and Toshiba was 70,000 in Oct-Dec 1996.)
* Pioneer (1996): 400,000 DVD-Video players in 1996, 11 million by 2000.
100,000 DVD-Audio players in 1996, 4 million by 2000.
* InfoTech (1996): 820,000 DVD-Video players in first year, 80 million by
* CEMA (1997): 400,000 DVD-Video players in U.S. in 1997, 1 million in
* Time-Warner (1996): 10 million DVD players in the U.S. by 2002.
* Paul Kagan (1997): 800,000 DVD players in the U.S. in 1997, 10 million
in 2000, and 40 million in 2006 (43% penetration). 5.6 million discs
sold in 1997, 172 million discs in 2000, and 623 million in 2006.
* C-Cube (1996): 1 million players and drives in 1997.
* BASES: 3 million DVD-Video players sold in first year, 13 million sold
in 6th year.
* Dataquest (1997): over 33 million shipments of DVD players and drives
* Philips (1996): 25 million DVD-ROM drives worldwide by 2000 (10% of
projected 250 million optical drives).
* Pioneer (1996): 500,000 DVD-ROM drives sold in 1997, 54 million sold in
* Toshiba (1996): 120 million DVD-ROM drives in 2000 (80% penetration of
100 million PCs). Toshiba says they will no longer make CD-ROM drives
* IDC (1997): 10 million DVD-ROM drives sold in 1997, 70 million sold in
2000 (surpassing CD-ROM), 118 million sold in 2001. Over 13% of all
software available on DVD-ROM in 1998. DVD recordable drives more than
90% of combined CD/DVD recordable market in 2001.
* AMI (1997): installed base of 7 million DVD-ROM drives by 2000.
* Intel (1997): 70 million DVD-ROM drives by 1999 (sales will surpass
CD-ROM drives in 1998).
* SMD (1997): 100 million DVD-ROM/RAM drives shipped in 2000.
* Microsoft (Peter Biddle, 1997): 15 million DVD-PCs sold in 1998, 50
million DVD-PCs sold in 1999.
* Forrester Research (1997): U.S. base of 53 million DVD-equipped PCs by
2002. 5.2% of U.S. households (5 million) will have a DVD-V player in
2002; 2% will have a DVD-Audio player.
* Yankee Group (Jan 1998): 650,000 DVD-Video players by 1998, 3.6 million
by 2001. 19 million DVD-PCs by 2001.
* InfoTech (Jan 1998): 20 million DVD-Video players worldwide in 2002, 58
million by 2005. 99 million DVD-ROM drives worldwide in 2005. No more
than 500 DVD-ROM titles available by the end of 1998. About 80,000
DVD-ROM titles available by 2005.
For comparison, there are about 700 million audio CD players and 160 million
CD-ROM drives worldwide in 1997. 1.2 billion CD-ROMs were shipped worldwide
in 1997 from a base of about 46,000 different titles. There are about 80
million VCRs in the U.S. (89% of households) and about 400 million
worldwide. There are about 250 million TVs in the US and 1.2 billion
worldwide. Estimated 1997 U.S. sales: 7.7 million VCRs, 900,000 projection
[1.10] What are "regional codes," "country codes," or "zone locks"?
Motion picture studios want to control the home release of movies in
different countries because theater releases aren't simultaneous (a movie
may come out on video in the U.S. when it's just hitting screens in Europe).
Also, studios sell distribution rights to different foreign distributors and
would like to guarantee an exclusive market. Therefore they have required
that the DVD standard include codes which can be used to prevent playback of
certain discs in certain geographical regions. Each player is given a code
for the region in which it's sold. The player will refuse to play discs
which are not allowed in that region. This means that discs bought in one
country may not play on players bought in another country.
Regional codes are entirely optional. Discs without codes will play on any
player in any country. It's not an encryption system, it's just one byte of
information on the disc that the player checks. Some studios have announced
that only their new releases will have regional codes, but so far almost all
releases play in only one region.
There are 6 regions (also called "locales"). Players and discs are
identified by the region number superimposed on a world globe. If a disc
plays in more than one region it will have more than one number on the
1: Canada, U.S., U.S. Territories
2: Japan, Europe, South Africa, Middle East (including Egypt)
3: Southeast Asia, East Asia (including Hong Kong)
4: Australia, New Zealand, Pacific Islands, Central America, South America,
5: Former Soviet Union, Indian Subcontinent, Africa (also North Korea,
(See the map at <http://www.unik.no/~robert/hifi/dvd/world.html>.)
Some players, such as the early Sony model, can be modified to play discs
regardless of their regional codes. This will probably void the warranty.
Regional codes also apply to DVD-ROM systems, but are allowed for use only
with DVD-Video discs, not DVD-ROM discs containing computer software. (See
1.11 below for more details). Operating systems including upcoming versions
of Windows and MacOS will check for regional codes before playing movies
from a DVD-Video. Some DVD-ROM kits let you change the region code a limited
number of times. It's likely that regional codes will apply to DVD-Audio.
[1.11] What are the copy protection issues?
There are three forms of copy protection used by DVD:
1) Videotape (analog) copying is prevented with a Macrovision 7.0 or similar
circuit in every player. The general term is APS (Analog Protection System).
Computer video cards with composite or s-video (Y/C) output must also use
APS. Macrovision adds a rapidly modulated colorburst signal ("Colorstripe")
along with pulses in the vertical blanking signal ("AGC") to the composite
video and s-video outputs. This confuses the synchronization and
automatic-recording-level circuitry in 95% of consumer VCRs. Unfortunately,
it can degrade the picture, especially with old or nonstandard equipment.
Macrovision may show up as stripes of color, distortion, rolling, black &
white picture, and dark cycling. Macrovision creates severe problems for
most line doublers. Macrovision is not present on analog component video
output of early players, but is required on newer players such as the Sony
S7000 (AGC only, since there is no burst in a component signal). The discs
themselves tell the player whether or not to enable Macrovision AGC with or
without Colorstripe. The producer of the disc decides what amount of copy
protection to enable and then pays Macrovision royalties accordingly. Just
as with videotapes, some DVDs are Macrovision-protected and some aren't.
(For a few Macrovision details see SGS/Thomson's video encoder datasheet at
2) Each disc also contains information specifying if the contents can be
copied. This is a "serial" copy generation management system (CGMS) designed
to prevent copies or copies of copies. The CGMS information is embedded in
the outgoing video signal. For CGMS to work, the equipment making the copy
must recognize and respect the CGMS. The analog standard (CGMS/A) encodes
the data on NTSC line 21. The digital standard (CGMS/D) is not yet
finalized, but will apply to digital connections such as IEEE 1394/Firewire.
3) Because of the potential for perfect digital copies, paranoid movie
studios forced a deeper copy protection requirement into the DVD-Video
standard. Content Scrambling System (CSS) is a form of data encryption to
discourage reading media files directly from the disc. Most players have a
decryption circuit that decodes the data before displaying it. No
unscrambled digital output is allowed until work in progress for secure
digital connections is finished. On the computer side, DVD-ROM drives and
video display/decoder hardware or software exchange encryption keys so that
the video is decrypted just before being displayed by the encoder. This
means that many DVD-ROM drives and video display boards have extra hardware
(and cost) for movie copy protection. In 1999, all DVD-ROM drives will be
required to support regional management in conjunction with CSS. Some drives
may allow the user to reset the region a limited number of times; other
drives will self-program after a certain number of movies have been played.
Makers of equipment used to display DVD-Video (drives, chips, display
boards, etc.) must license CSS. There is no charge for a CSS license, but
it's currently a lengthy process, so it's recommended that interested
parties apply as soon as possible. Near the end of May 1997, CSS licenses
were finally granted for software decoding.
Movie studios and consumer electronics companies want to make it illegal to
defeat DVD copy protection, and are pursuing legislation in the U.S. and
other countries. A co-chair of the legal group of the copy protection
committee stated, "in the video context, the contemplated legislation should
also provide some specific assurances that certain reasonable and customary
home recording practices will be permitted, in addition to providing
penalties for circumvention." It's not at all clear how this might be
"permitted" by a player.
CSS is allowed for DVD-video content only. Of course, since a DVD-ROM can
hold any form of computer data, any desired encryption scheme can be
All three forms of copy protection are optional for the producer of a disc.
Movie decryption is also optional for hardware and software playback
manufacturers: a player or computer without decryption capability will only
be able to play unencrypted movies.
These copy protection schemes are designed only to guard against casual
copying (which the studios claim causes billions of dollars in lost
revenue). The goal is to "keep the honest people honest." Even the people
who developed the copy protection standards admit that it won't stop
well-equipped pirates. There are inexpensive devices that defeat analog copy
protection, but Macrovision claims none of the devices are effective against
the new Colorstripe feature (yet).
Macrovision and DigiMarc have proposed a watermark process for DVD, which
permanently marks each video frame with visually undetectable information.
This can be recognized by video equipment to prevent copying, even when the
video is transmitted digitally. New players and other equipment will be
required to support watermarking. It's possible to make new watermarked
discs compatible with existing players, but movie studios will probably not
[1.12] What about DVD-Audio or Music DVD?
The DVD Consortium has decided to seek additional input from the music
industry before defining the DVD-Audio format. An audio standard probably
won't appear until the end of 1997 at the earliest, and products probably
won't appear before 1999. If the final specification includes features or
formats not present in the current DVD specification, existing DVD players
may not be able to play new DVD-Audio discs.
Sony is pushing for its Super Audio CD format based on Direct Stream Digital
(DSD), with the support of Philips. Other organizations such as Acoustic
Renaissance for Audio (ARA) prefer lossless compressed PCM that's more
appropriate for studio work and archiving. Informed rumor has it that PCM
will be mandatory and other formats will be optional. Dolby Digital rates
may be allowed to go higher than the 448-kbps limit of DVD-Video, or even
the 640 kbps limit of most current decoders.
There are rumors that the DVD Consortium is pushing for an 8 cm (CD-single)
size, while the audio industry wants a 12 cm size. (The existing DVD
physical spec allows both sizes.) The audio industry also wants "legacy"
discs which will play on one side in existing CD players and on the other
side in DVD players. The Super Audio CD format supports this.
The music industry is also requesting an "embedding signalling" or "digital
watermark" copy protection feature. This uses pit signal processing
technology to apply a digital signature and optional encryption keys to the
audio in the form of supposedly inaudible noise so that new equipment will
recognize copied audio and refuse to play it. Audiophiles claim this
degrades the audio.
In the meantime, the DVD-Video standard includes surround sound audio and
better-than-CD audio (see 3.6). Pioneer is developing audio-only players
based on the audio portion of DVD-Video.
[1.13] Which studios are supporting DVD?
Warner, Columbia TriStar, MGM, Polygram, Paramount, Disney, Fox
(unofficially), and others are releasing movies on DVD (see 6.2 for a full
list; see 1.6 for movie info). Paramount so far has only officially
announced support for Divx, but they are known to be working on regular
[1.14] Can DVD record from VCR/TV/etc?
Short Answer: No. (Not in this century.)
Long answer: The minimum requirement for reproducing audio and video on DVD
is an MPEG video stream and a PCM audio track. (Other streams such as Dolby
Digital audio, MPEG audio, and subpicture are not necessary for the simplest
case.) Basic DVD control codes are also needed. At the moment it's difficult
in real time to encode the video and audio, combine them with the control
codes, and write the whole thing to DVD. Even if you could do all this in a
home recorder, it would be extremely expensive. Prices for DVD production
systems are dropping from millions of dollars to thousands of dollars, but
they won't be in the <$500 range for home use for several years yet. In June
1997, Hitachi demonstrated a home DVD video recorder containing a DVD-RAM
drive, a hard disk drive (as a buffer), two MPEG-1 encoders, and an MPEG-2
decoder. No production date was mentioned. It's possible the first home DVD
recorders will require a digital source of already-compressed audio and
video, such as DBS.
Other obstacles: Price of blank discs may initially be as high as $40. The
first generation of recordable media will hold less than 3/4 as much as
pre-recorded discs. Realtime compression requires higher bit rates for
decent quality, lowering capacity even more. MPEG-2 compression works much
better with high-quality source, so recording from VHS or broadcast/cable
may not give very good results (unless the DVD recorder has prefilters,
which raises the cost).
Don't be confused by DVD-RAM and DVD-R systems, which will be available soon
and will cost $800 to $17,000 (see 4.3). These can record data, but to
create full-featured DVD-Videos would require additional hardware and
software to do video encoding (MPEG-2), audio encoding (Dolby Digital or
MPEG or LPCM), subpicture encoding (run-length-compressed bitmaps), still
frame encoding (MPEG-1 or MPEG-2), control code generation, and
multiplexing. And since this can't be done in real time, you'd also need a 5
to 9 GB hard drive to premaster the data to.
Some people believe that recordable DVD-Video will never be practical for
consumers to record TV shows or home videos, since digital tape is more cost
effective. On the other hand, digital tape lacks many of the advantages of
DVD such as seamless branching, instant rewind/fast forward, instant search,
and durability, not to mention the coolness of small shiny discs. So once
the encoding technology is fast and cheap enough, and the blank discs are
cheap enough, recordable DVD may be a reality. It will be an interesting
contest between DVD and digital video tape (DV). DV is out already, but
decks cost $4,000.
[1.15] What happens if I scratch the disc? Aren't discs too fragile to be
Most scratches will cause minor channel data errors that are easily
corrected. A common misperception is that a scratch will be worse on a DVD
than on a CD because of higher storage density and because video is heavily
compressed. DVD data density (say that fast ten times!) is physically four
times that of CD-ROM, so it's true that a scratch will affect more data. But
DVD error correction is at least ten times better and more than makes up for
the density increase. It's also important to realize that MPEG-2 and Dolby
Digital compression are partly based on removal or reduction of
imperceptible information, so decompression doesn't expand the data as much
as might be assumed. Major scratches may cause uncorrectable errors that
will cause an I/O error on a computer or show up as a momentary glitch in
DVD-Video picture. There are many schemes for concealing errors in MPEG
video, which may be used in future players (see section D.12 of
The DVD computer advisory group specifically requested no mandatory caddies
or other protective carriers. Consider that laserdiscs, music CDs, and
CD-ROMs are likewise subject to scratches, but many video stores and
libraries rent them. Major chains such as Blockbuster and West Coast
Entertainment rent DVDs in many locations. So far most reports of rental
disc performance are positive. A nice list of DVD rental outlets is at
[1.16] VHS is good enough, why should I care about DVD?
The primary advantages of DVD are quality and extra features (see 1.2). DVD
will not degrade with age or after many playings like videotape will (which
is an advantage for parents with kids who watch Disney videos twice a
week!). This is the "collectability" factor present with CDs vs. cassette
If none of this matters to you, then VHS probably is good enough.
[1.17] Is the packaging different from CD?
Manufacturers are worried about customers assuming DVDs will play in their
CD player, so they would like the packaging to be different. Time Warner is
promoting a "Snapper" package (similar in form to the plastic and paper
"eco" CD packages) which measures 14cm wide x 19cm high x 1.25cm thick (5.5"
x 7.5" x 0.5"). [I measured it by hand, so this may not be exact.] This is
about as wide as a CD jewel box and about as tall as a VHS cassette box.
There is also a proposal from the Video Software Dealers Association for a
package 5 5/8" wide, 7 3/8" high and between 3/8" and 5/8" deep. However, no
one is being forced to use a larger package size and many companies will
undoubtedly use standard jewel cases. It remains to be seen if any package
becomes standard, especially for DVD-ROM.
[1.18] What's a dual-layer disc? Will it work in all players?
A dual-layer disc has two layers of data, one of them semi-transparent.
Since both layers are readable from the same side, a dual-layer disc can
hold almost twice as much as a single-layer disc, for over 4 hours of video
(see 3.3 for more details). Many dual-layer discs are currently available
(such as Contact, Goldeneye, Species, Raging Bull, and Rain Man). Initially
only a few replication plants could make dual-layer discs, but most plants
now have the capability. The second layer can either have a "PTP" track that
runs in parallel to the first track (for independent data or special
switching effects), or an "OTP" tracks that runs opposite to the first
track; that is the pickup head reads out from the center on the first track
then in from the outside on the second track. This is designed to provide
continuous video across both layers. There's no guarantee that the switch
between layers will be seamless. Non-seamless switches cause the video to
freeze for less than half a second on most players but up to 4 seconds on
some. The "seamlessness" depends as much on the way the disc is prepared as
on the design of the player. OTP is also called RSDL (Reverse-Spiral Dual
Layer). The advantage of OTP (RSDL) is that longer movies can use higher
data rates for better quality than with a single layer. See 1.26 for layer
All DVD players and drives can read dual-layer discs -- it's required by the
spec. All players and drives also play double-sided discs if you flip them
over. No manufacturer has announced a model that will play both sides. The
added cost is probably not justifiable since discs can hold over 4 hours of
video on one side by using two layers. (Early discs used two sides because
dual-layer production was not widely supported. This should no longer be a
problem.) Pioneer LD/DVD players can play both sides of an LD, but not a
DVD. (See 2.9 for note on reading both sides simultaneously.)
There are various ways to recognize dual-layer discs: 1) the gold color, 2)
a menu on the disc for selecting the widescreen or letterbox version, 3) two
serial numbers on one side.
[1.19] Is DVD-Video a worldwide standard? Does it work with NTSC, PAL, and
DVD-V has the same NTSC vs. PAL problem as videotape and laserdisc. DVD-V
supports two mutually-incompatible television systems: 525/60 (NTSC) and
625/50 (PAL/SECAM). There are three differences between discs intended for
playback on different systems: picture size (720x480 vs. 720x576), display
frame rate (29.97 vs 25), and surround audio (Dolby Digital vs. MPEG). (See
3.4 and 3.6 for details.) Movies are stored at 24 frames/sec but must be
preformatted for one of the two display rates. Movies formatted for PAL
display are usually sped up by 4%, so the audio must be adjusted accordingly
before being encoded.
Some players will only play NTSC discs, some players will only play PAL
discs, and some will play both. Most European players play both. These
multi-standard players output NTSC from a 525/60 disc and PAL from a 625/50
disc. This requires two TVs or a multi-standard TV. Some players partially
convert NTSC to 60 Hz PAL, which requires a 60 Hz PAL TV. It's also possible
to make a standards-converting player that will output standard NTSC from a
625/50 disc or standard PAL from a 525/60 disc, but no such players have
A producer can choose to include additional video and audio --at the expense
of playing time-- so that all formats are covered. It's unclear if players
will be able to automatically recognize and play the correct video track. Of
course it's always possible to put 525/60 video on one side of the disc and
625/50 on the other. Most studios so far are including Dolby Digital tracks
along with the MPEG audio tracks on their PAL discs.
There are actually three types of DVD players if you count computers. Most
DVD playback software and hardware can play both NTSC and PAL video.
[1.20] What about animation on DVD? Doesn't it compress poorly?
Some people claim that animation, especially hand-drawn cell animation such
as cartoons and anime, does not compress well with MPEG-2 or even ends up
larger than the original. Other people claim that animation is simple so it
compresses better. Neither is true.
Supposedly the "jitter" between frames caused by differences in the drawings
or in their alignment causes problems. An animation expert at Disney pointed
out that this doesn't happen with modern animation techniques. And even if
it did, the motion estimation feature of MPEG-2 would compensate for it.
Because of the way MPEG-2 breaks a picture into blocks and transforms them
into frequency information it can have a problem with the sharp edges common
in animation. This loss of high-frequency information can show up as
"ringing" or blurry spots along edges (called the Gibbs effect). However, at
the data rates commonly used for DVD this problem does not occur.
[1.21] Why do some discs require side flipping? Can't DVDs hold four hours
Even though DVD's dual-layer technology (see 3.3) allows over four hours of
continuous playback, some movies are split over two sides of a disc,
requiring that it be flipped partway through (no players can automatically
flip the disc yet). This is usually because the producers were too lazy to
optimize the compression or to make a dual-layer disc. Better picture
quality is a lame excuse for increasing the data rate; in many cases the
video will look better if carefully encoded at a lower bit rate. Lack of
dual-layer production capability is also a lame excuse; at first very few
DVD plants could make dual-layer discs, but this is no longer the case.
Unless a movie is more than 4 hours long, it can easily fit on one
dual-layer (RSDL) side. The following movies require flipping. (Note: This
is not the same as a disc with a widescreen version on one side and a pan &
scan version on the other.)
* The Color Purple
* Das Boot: The Director's Cut
* Dawn of the Dead
* An Evening of Yes Music Plus - Anderson Bruford Wakeman Howe
* Gloria Estefan Live in Miami, the Evolution Tour
* The Green Berets
* Into the Woods
* Live! At Knebworth
* Loud and Live - Ozzy Osbourne
* The Man Who Would Be King
* Michael Collins
* The Pelican Brief
* The Player (movie on one side, extras on other)
* The Right Stuff
* Robin Hood Prince of Thieves
* Spawn - The Animated Series
* Stargate (Note: A dual-layer special edition of Stargate is planned for
* A Time to Kill
* The Wild Bunch
[1.22] Why is the picture squished, making things look too skinny?
Answer: RTFM. You are watching an anamorphic picture intended for display
only on a widescreen TV. (See 3.5 for technical details). You need to go
into the player's setup menu and tell it you have a standard 4:3 TV, not a
widescreen 16:9 TV. It will then automatically letterbox the picture so you
can see the full width at the proper proportions. In some cases you can
change the aspect ratio as the disc is playing (by pressing the "aspect"
button on the remote control. On Pioneer players, you have to stop the disc
before you can change aspect.
[1.23] Do all videos use Dolby Digital (AC-3)? Do they all have 5.1
Most DVD-Video discs contain Dolby Digital soundtracks. However, it's not
required. Some discs, especially those containing only audio, have PCM
tracks. It's also possible for a 625/50 (PAL) disc to contain only MPEG
audio, but so far MPEG audio is not widely used.
Do not assume that the "Dolby Digital" label is a guarantee of 5.1 channels.
A Dolby Digital soundtrack can be mono, dual mono, stereo, Dolby Surround
stereo, etc. For example, Blazing Saddles and Caddyshack are mono movies, so
the Dolby Digital soundtrack on these DVDs has only one channel. Some DVD
packaging has small lettering or icons under the Dolby Digital logo that
indicates if there are 5.1 channels. In some cases, there are more than one
Dolby Digital tracks: a 5.1-channel track and a track specially remixed for
stereo Dolby Surround.
See 3.6 for more audio details.
[1.24] Can DVDs have laser rot?
Laserdiscs are subject to what's commonly called laser rot: the
deterioration of the aluminum layer due to oxidation. The large size of
laserdiscs makes them flexible, so that movement along the bond between
sides can break the seal. DVDs are much more rigid. Also, DVDs are molded
from polycarbonate, which absorbs about ten times less moisture than the
PMMA used for laserdiscs. It's too early to know for sure, but DVD's will
probably have few or no laser rot problems.
[1.25] Which titles are pan & scan only? Why?
Some titles are available only in pan & scan because there was no letterbox
or anamorphic transfer made from film. (See 3.5 for more info on pan &
scan.) Since transfers cost $50,000 to $100,000, studios may not think a new
transfer is justified. In some cases the original film or rights to it are
no longer available for a new transfer. In the case of old movies, they were
shot full frame so there is no widescreen version. The following DVD titles
are pan & scan or full frame. A detailed list is also available at
<http://www.unik.no/~robert/hifi/dvd/film1.html>. A list of anamorphic
titles is available at <http://www.laserviews.com/16x9.html>.
* The Bodyguard
* Bonnie & Clyde
* Bridges of Madison County
* Chariots of Fire
* Driving Miss Daisy
* Grumpy Old Men
* My Fellow Americans
* Fly Away Home
* Space Jam
[1.26] How do I make the subtitles on my Pioneer player go away?
On the remote control, press Subtitle, then either Clear or 0 (zero). No
need to use the menus.
[1.27] What is a layer change? Where is it on specific discs?
Some movies over 2 hours long may be spread across two layers on a disc.
When the player changes to the second layer, the video and audio may freeze
for a moment. The length of the pause depends on the player and on the
layout of the disc. The pause is not a defect in the player or the disc. See
1.18 for details.
Layer changes on RSDL discs:
* Contact: 1:00:34 (cut to fax from Hadden)
* The Good, the Bad, and the Ugly: 1:29:21 (Tuco asked if he'd like
* Platoon: ?
* Terminator 2: 1:19:45 (close up of knife in table)
* Waterworld: 0:58:54 (cut to boxes of SMEAT and VODKA)
Rumored future RSDL discs:
* Apollo 13
* Once Upon A Time In America
[1.28] The disc says Dolby Digital. Why do I get 2-channel surround audio?
Some discs (many from Columbia TriStar) put 2-channel Dolby Surround audio
on track one and 5.1-channel audio on track two. Unless you intervene, the
player will play the default 2-channel track. Use the audio button on the
remote or select the 5.1 track from the menu. (Note: The Sony 3000 has a
feature to automatically select the first 5.1 track.)
Dolby Digital doesn't necessarily mean 5.1 channels. See 3.6.
 DVD's relationship to other products
[2.1] Will DVD replace VCRs?
Not any time soon. Recordable DVD is for computer data only, not television
video (see 1.14). It will take a while before the size of the market drives
costs down to VCR levels. However, DVD has many advantages over VCRs,
including fundamentally lower technology cost for hardware and disc
production (which is appealing to manufacturers), so if DVD is a commercial
success it might replace many VCRs in fifteen to twenty years.
[2.2] Will DVD replace CD-ROM?
Yes. Some CD-ROM drive manufacturers plan to cease CD-ROM drive production
after a few years in favor of DVD-ROM drives. Because DVD-ROM drives can
read CD-ROMs, there is a compatible forward migration path.
[2.3] Can CD-R writers create DVDs?
No. DVD uses a smaller wavelength of laser to allow smaller pits in tracks
that are closer together. The DVD laser must also focus more tightly and at
a different level. In fact, a disc made on a current CD-R writer may not be
readable by a DVD-ROM drive (see 2.4.3). It's unlikely there will be
"upgrades" to convert CD-R drives to DVD-R, since this would probably cost
more than purchasing a new DVD-R drive.
[2.4] Is CD compatible with DVD?
This is actually many questions with many answers:
[Note the differentiation between DVD (general case) and DVD-ROM (computer
[2.4.1] Is CD audio (CD-DA) compatible with DVD?
Yes. All DVD players and drives will read audio CDs (Red Book). This is not
actually required by the DVD spec, but so far all manufacturers have stated
that their DVD hardware will read CDs. On the other hand, you can't play a
DVD in a CD player. (The pits are smaller, the tracks are closer together,
the data layer is a different distance from the surface, the modulation is
different, the error correction coding is new, etc.)
[2.4.2] Is CD-ROM compatible with DVD-ROM?
Yes. All DVD-ROM drives will read CD-ROMs (Yellow Book). However, DVD-ROMs
are not readable by CD-ROM drives.
[2.4.3] Is CD-R compatible with DVD-ROM?
Sometimes. The problem is that CD-Rs (Orange Book Part II) are "invisible"
to DVD laser wavelength because the dye used in CD-Rs doesn't reflect the
beam. Some first-generation DVD-ROM drives and many DVD players can't read
CD-Rs. The solution is to use an optical pickup with two lasers at different
wavelengths: one for reading DVDs and the other for reading CDs and CD-Rs.
To guarantee compatibility, look for drives with the MultiRead label, which
guarantees compatibility with CD-R and CD-RW media.
An effort to develop CD-R "Type II" media compatible with both CD and DVD
wavelengths has been abandoned.
[2.4.4] Is CD-RW compatible with DVD?
Supposedly. CD-Rewritable (Orange Book Part III) has a lower reflectivity
difference, requiring new automatic-gain-control (AGC) circuitry. CD-RW
discs can't be read by most existing CD-ROM drives and CD players. The new
"MultiRead" standard addresses this, and some DVD manufacturers have
suggested they will support it. Supposedly the optical circuitry of DVD-ROM
drives and DVD players is good enough to read CD-RW. CD-RW does not have the
"invisibility" problem of CD-R (see 2.4.3).
[2.4.5] Is Video CD compatible with DVD?
Sometimes. It's not required by the DVD spec, but it's trivial to support
the White Book standard since any MPEG-2 decoder can also decode MPEG-1 from
a Video CD. Panasonic, RCA, Samsung, and Sony models play Video CDs.
Japanese Pioneer models play Video CDs but American models don't. Toshiba
players don't play Video CDs.
VCD resolution is 352x288 for PAL and 352x240 for NTSC. The way most DVD
players and Video CD players deal with the difference is to chop off the
extra lines or add blank lines. When playing PAL VCDs, the Panasonic and RCA
NTSC players apparently cut 48 lines (17%) off the bottom. The Sony NTSC
players apparently scale all 288 lines to fit.
Most DVD-ROM computers will be able to play Video CDs (with the right
software), since its already possible with current-model CD-ROM computers.
Note: Many Asian VCDs achieve "two" soundtracks by putting one language on
the left channel and another on the right. They will be mixed together into
babel on a stereo system unless you adjust the balance to get only one
[2.4.6] Is Photo CD compatible with DVD?
Not yet. Since Photo CDs are usually on CD-R media, they may suffer from the
CD-R problem (see 2.4.3). That aside, DVD players could support Photo CD
with a few extra chips and a license from Kodak. No one has announced such a
player. Most DVD-ROM drives will read Photo CDs (if they read CD-Rs) since
it's trivial to support the XA and Orange Book multisession standards. The
more important question is, "Does the OS or application support Photo CD?"
but that's beyond the scope of this FAQ.
[2.4.7] Is CD-i compatible with DVD?
In general, no. Most DVD players will not play CD-i (Green Book) discs.
However, Philips has announced that it will make a DVD player that supports
CD-i. Some people expect Philips to create a "DVD-i" format in attempt to
breathe a little more life into CD-i (and recover a bit more of the billion
or so dollars they've invested in it).
[2.4.8] Is Enhanced CD compatible with DVD?
Yes. DVD players will play music from Enhanced Music CDs (Blue Book, CD
Plus, CD Extra), and DVD-ROM drives will play music and read data from
Enhanced CDs. Older ECD formats such as mixed mode and track zero (pregap,
hidden track) should also be compatible, but there may be a problem with
DVD-ROM drivers skipping track zero (as has been the case with some new
[2.4.9] Is CD+G compatible with DVD?
Only the Pioneer DVL-9 player and Pioneer karaoke DVD models DV-K800 and
DVK-1000 are known to support CD+G. Most other DVD-V players probably won't
support this mostly obsolete format. All DVD-ROM drives support CD+G, but
special software is required to make use of it.
[2.4.10] Is CDV compatible with DVD?
Sort of. CDV, sometimes called Video Single, is actually a weird combination
of CD and laserdisc. Part contains 20 minutes of digital audio playable on
any CD or DVD player. The other part contains 5 minutes of analog video (and
digital audio) in laserdisc format, playable only on a CDV-compatible
system. However, Pioneer and others have announced combination players that
will play DVDs, laserdiscs, and CDVs.
[2.4.11] Is MP3 compatible with DVD?
No. MP3 is MPEG-1 Layer 3 audio compression. The DVD-Video spec allows Layer
2 only. MP3 can be played on a computer with a DVD-ROM drive, but not in a
[2.5] Is laserdisc compatible with DVD?
No. Standard DVD players will not play laserdiscs, and you can't play a DVD
disc on any standard laserdisc player. (Laserdisc uses analog video, DVD
uses digital video; they are very different formats.)
However, Pioneer and Samsung have announced combo players that will play
laserdiscs and DVDs (and also CDVs and audio CDs). Denon is rumored to have
an LD/DVD player in the works also.
[2.6] Will DVD replace laserdisc? Should I buy laserdisc now or wait for DVD
DVD will probably replace laserdisc, but not for a very long time. Laserdisc
is well established as a videophile format. There are over 9,000 laserdisc
titles in the US and a total of over 35,000 worldwide that can be played on
over 7 million laserdisc players. It will take DVD many years to reach this
point. Until then laserdisc has the superiority of tenure. Pioneer and other
laserdisc companies have committed to supporting it for years to come.
There's no reason to stop buying laserdiscs, especially rare titles that may
not appear on DVD for a long while if ever. Even laserdisc owners who buy
DVD will not immediately replace their collection. Laserdisc and DVD will
co-exist for a long while.
In December of 1996 the FCC approved the U.S. DTV standard. HDTVs will be
available in late 1998 or early 1999 but they will be very expensive and
won't become widespread for many years. DVD will look better on HDTVs but it
won't provide high resolutions. See 2.9 for more information on DVD and
The final answer to this question depends on you. If you need to be the
first on your block with the latest gadget, you may want to get a DVD player
or a combination LD/DVD player now. If you prefer to wait until DVD prices
drop and bugs get worked out, you may have a lengthy wait. If you think DVD
isn't a big enough improvement and decide to hold out for HTDV, you'll be in
for an even longer wait. In the meantime you could be enjoying the large
selection of laserdisc titles. Or you could start saving now for DVD (which
won't be too expensive) or HDTV (which will be). If you buy a laserdisc
player, a surround sound system, and speakers, they will be still be useful
even after DVD and HDTV come out. HDTV will require a new TV set, but it
will be compatible with the rest of your gear.
Unfortunately, laserdisc was hurt by anticipation of DVD before it even came
out. In 1996 laserdisc player sales were down 37% even though sales of VCRs
and hi-fi/surround systems were up. The silver lining in this cloud is that
disc prices came down. (Laserdisc movie sales were only down 2.5% in 1996.)
[2.7] How does DVD compare to laserdisc?
This is a dangerous question to answer, given the legions of laserdisc
fanatics who would rather have their laserdiscs pried from their cold dead
fingers than switch! But I'm a bit fanatical myself: I've used laserdiscs
since 1979 and I work for a company whose major product is laserdiscs; so
I'll give it a shot. <Putting on flameproof suit....>
* Features: DVD has the same basic features as CLV LD (scan, pause,
search) and CAV LD (freeze, slow) and adds branching, multiple camera
angles, parental control, video menus, interactivity, etc. Some of
these features will not be widely available, especially at first.
Unlike CAV LD, DVD can't play backwards, single-step backwards, or do
bi-directional multispeed (until the players get more video memory).
* Capacity: Single-layer DVD holds over 2 hours, dual-layer holds over 4
hours. CLV LD holds one hour per side, CAV holds half an hour. DVD can
also hold hundreds of still pictures accompanied by over 20 hours of
audio and text.
* Convenience: An entire movie fits on one side of a DVD, so there's no
need to flip the disc or wait for the player to do it. DVDs are smaller
and easier to handle. DVD players can be portable, similar to CD
players. Discs can be easily and cheaply sent through the mail. On the
other hand, laserdiscs have larger covers for better art and text.
* Noise: Most LD players make a whirring noise that can be heard during
quiet segments of a movie. Some DVD players are as quiet as CD players,
others are noisier.
* Audio: LD has better quality on Dolby Surround soundtracks. DVD has
better quality on Dolby Digital or music only. LD has 2 audio tracks:
analog and digital. DVD has up to 8 audio tracks. LD uses PCM audio
sampled with 16 bits at 44 kHz. DVD LPCM audio can use 16, 20, or 24
bit samples at 48 or 96 kHz (although PCM won't be used with most
movies). LD has surround audio in Dolby Surround, Dolby Digital (AC-3),
and DTS formats. 5.1-channel surround sound is available by using one
channel of the analog track for AC-3 or both channels of the digital
track for DTS. DVD uses the same Dolby Digital surround sound, usually
at the same data rate (384 kbps) but can go up to 448 kbps for better
quality, and can optionally include DTS (at data rates up to 1536 kbps
compared to LD's 1411 kbps, but in practice DTS data rates will
probably be lower on DVD than on LD). DVD players convert Dolby Digital
to Dolby Surround. This conversion (downmix) process can reduce dynamic
range. Combined with the effects of compression, this usually results
in lower-quality sound than from LD Dolby Surround tracks.
* Video: DVD usually has better video. LD suffers from degradation
inherent in analog storage and in the composite NTSC or PAL video
signal. DVD uses digital video, and even though it's heavily
compressed, most professionals agree that when properly and carefully
encoded it's virtually indistinguishable from studio masters.
Nevertheless, this doesn't mean that the video quality of DVD,
especially at first, WILL be better than LD. Only that it CAN be
better. Also keep in mind that the average television is of
insufficient quality to show much difference between LD and DVD. Home
theater systems or HDTVs are needed to take full advantage of the
improved quality. The arguments about DVD quality vs. LD quality will
rage for a long time. The only final answer is to compare them side by
side and form your own opinion.
* Resolution: In numerical terms DVD has 345,600 pixels (720x480), which
is 1.3 times LD's approximately 272,160 pixels (567x480). Widescreen
DVD has 1.7 times the pixels of letterboxed LD (or 1.3 times anamorphic
LD). As for lines of horizontal resolution, DVD ~= 500, LD ~= 425, and
VHS ~= 240. (All figures are for NTSC, not PAL.)
* Support: There are many more laserdisc players and discs. But there are
already more announced DVD players than there are LD players. Many new
computers will also be able to play DVD-Videos.
* Price: DVD players are not yet cheaper than the cheapest LD player, but
the success of DVD-ROM will inevitably drive the price to level of CD
players. Most movies on DVD cost less than on LD, except when priced
* Restrictions: For those outside the US, regional coding (see 1.10) is a
definite drawback of DVD. For some people Macrovision copy protection
(see 1.11) is an annoyance. Laserdisc has no copy protection and does
not have regional differences other than PAL vs. NTSC.
Again, it will take years for DVD to reach the number of titles, installed
base, and even quality of production that laserdisc has. DVD and laserdisc
will coexist for at least another decade. But the potential of DVD can't be
ignored -- it's the most likely long-term successor to laserdisc.
For more laserdisc info, see the Laserdisc FAQ at
[2.8] Can I modify or upgrade my laserdisc player to play DVD?
It's not likely. DVD circuitry is completely different, the pickup laser is
a different wavelength, the tracking control is more precise, etc. No
hardware upgrades have been announced, and in any case they would probably
be more expensive than buying a DVD player to put next to the laserdisc
[2.9] Does DVD support HDTV (DTV/ATV)? Will HDTV make DVD obsolete?
Short answers: Partially. No.
DVD-Video does not directly support HDTV. No HDTV standards were finalized
when DVD was developed. In order to be compatible with existing televisions,
DVD's MPEG-2 video resolutions and frame rates are closely tied to NTSC and
PAL/SECAM video formats. DVD does use the 16:9 aspect ratio of HDTV. Since
most HDTV systems are based on MPEG-2, it would be easy to "upgrade" the
existing DVD format. The limited data rate of DVD may make it difficult to
support high-quality HDTV, but this can be solved by increasing the spin
rate (a double-speed DVD-ROM drive exceeds the 19 Mbps US DTV data rate) or
by using higher-capacity blue or purple lasers (already demonstrated by many
DVD manufacturers). Either case will require new players and additional DVD
The resolution and frame rates of DTV in the US will probably correspond to
the ATSC recommendations: 704x480 (24P, 30P, 60I, 60P), 1280x720 (60P),
1920x1080 (30P). The first set is "standard definition" and matches DVD.
It's expected that future DVD players will convert video from existing discs
to SDTV formats (all but 60P). The second two HDTV formats are "high
definition" at 2.7 and 6 times the resolution of DVD. The 60P version is
twice the frame rate. The ITU-R is working on BT.709 HDTV standards of
1125/60 (1920x1035/30) (same as SMPTE 240M, similar to Japan's analog MUSE
HDTV) and 1250/50 (1920x1152/25) which may be used in Europe. The latter is
5.3 times the resolution of DVD's 720x576/25 format. In other words,
DVD-Video does not currently support the higher levels of HDTV systems.
HDTV will not make DVD obsolete. Those who postpone purchasing a DVD player
because of HDTV are in for a long wait. HDTV sets will become available in
late 1998 or early 1999 at very high prices (about $8000 and up). It will
take many years before even a small percentage of homes have HDTV sets. CEMA
expects 10 percent of U.S. households to have HDTV in 2003, 20 percent by
2005, and 30 percent by 2006.
HTDV sets will include analog video connectors (composite, s-video, and
component) that will work with all DVD players and other existing video
equipment such as VCRs. Existing DVD players and discs will work perfectly
with HDTV sets, and will provide a much better picture than any other
prerecorded consumer video format, especially once new progressive-scan
players become available. Since the cheapest route to HDTV reception will be
HDTV converters for existing TV sets, HDTV for many viewers will look no
better than DVD.
At some point, HDTV displays will support component digital video
connections (YCrCb) or digital data connections (FireWire/IEEE 1394). The
digital connections will provide the best possible reproduction of
DVD-Video, especially in widescreen mode. Once DVD players have digital
outputs, they may be usable as "transports" which output any kind of A/V
data (even formats developed after the player was built) to any sort of
external display or converter.
Eventually there will be a "DVD-HD" format, probably around 2003 at the
earliest. DVD-HD players will play current DVD discs and will make them look
even better. Ironically, DVD-ROM computers will support HDTV before
DVD-Video players, since 2x drives coupled with appropriate playback and
display hardware can already meet all the requirements for HDTV.
Some have speculated that a "double-headed" player reading both sides of the
disc at the same time could double the data rate for applications such as
HDTV. This is currently impossible since the track spirals go in opposite
directions (unless all four layers are used). The DVD spec would have to be
changed to allow reverse spirals on layer 0. Even then, keeping both sides
in sync, especially with MPEG-2's variable bit rate, would require
independently tracking heads, precise track and pit spacing, and a larger,
more sophisticated track buffer.
Note: The term "HDVD" has already been taken for "High-density Volumetric
[2.10] What's Divx?
Depending on whom you ask, Divx (formerly ZoomTV) is either an insidious
evil scheme for greedy studios to control what you see in your own living
room or an innovative approach to video rental that lets you get discs
almost anywhere and keep them for later viewings. Regardless, Divx will
confuse consumers and delay the acceptance of DVD. Developed by Circuit City
and a Hollywood law firm, Divx was announced for Summer 1998 release, which
means players and discs probably won't be available until Fall of 1998.
Disney (Buena Vista), Paramount, Universal, and Dream Works will release
Divx discs. JVC, Matsushita (Panasonic), Thomson (RCA/Proscan/GE), and
Zenith are developing Divx players. Reportedly the studios supporting DVD
were offered incentives totalling $20 million.
Divx is essentially a pay-per-view variation of DVD. Divx discs will be sold
for about $5 to $7. Once inserted into a Divx player the disc will play
normally for the next 48 hours, after which the "owner" must pay about $3 to
$5 to unlock it for another 48 hours. The Divx DVD player must be hooked up
to a phone line so it can call an 800 number during the night a few times a
month to upload billing information. Special Divx Silver discs can be
permanently unlocked by paying a higher fee, and unlimited-playback Divx
Gold discs may also be offered for sale at a price similar to regular "open"
DVDs. Divx players also play regular DVD discs, but Divx discs do not play
in standard DVD players. Divx discs are serialized (with a barcode in the
standard Burst Cutting Area) and in addition to normal DVD copy protection
(see 1.11) they employ watermarking and triple DES encryption. No computer
support of Divx has been announced, and in any case special decryption
hardware would be required since DES is too complex for realtime software
decoding. Because of the DES encryption, Divx technology may not be allowed
outside the U.S.
Advantages of Divx:
* Viewing can be delayed, unlike rentals.
* Discs need not be returned. No late fees.
* You can watch the movie again for a small fee. Initial cost of "owning"
a disc is reduced.
* The disc is new; no damage from previous renters.
* The "rental" market is opened up to other retailers, including mail
* Studios get more control over their content.
Disadvantages of Divx:
* Higher player cost (about $100 more, may eventually drop to $50 more).
* Higher cost than for regular DVD rental ($4 to $5 vs $2 to $3). As a
monopoly, there are few obstacles to the company raising prices later.
* Casual viewing (looking for a name in the credits, playing a favorite
scene, watching supplements) will require paying a fee.
* Initial Divx titles are planned to be pan & scan.
* The player must be hooked to your phone line, possibly requiring a new
jack in your living room or a wire strung across it.
* If your phone line is down for a period of time you may not be able to
watch Divx discs.
* Divx is collecting information about your viewing habits.
* Divx players include a "mailbox" for companies to send you unsolicited
* Those who don't lock out their Divx player may receive unexpected bills
when their kids or visitors play Divx discs.
* Divx discs won't play in regular DVD players or on PCs with DVD-ROM
drives. Uninformed consumers may buy Divx discs only to find they won't
play in their non-Divx player.
* Unlocked discs (including Gold discs) will only work in players owned
by the customer. Playback in a friend's Divx player will incur a
* Divx can't be used in mobile environments, such as a van or RV.
* No market for used discs.
* Divx could undermine the DVD rental business and sellthrough business
(possibly resulting in higher costs for non-Divx discs).
* If Divx goes out of business, Divx discs will be unplayable.
* Divx players may never be available outside the U.S.
For more information, see the Divx FAQ at <http://www.divx.com> and the Anti
Divx page at <http://www.dvdresource.com/divx>.
 DVD technical details
[3.1] What are the outputs of a DVD player?
Most DVD players have the following output connections:
- Composite video (CVBS) RCA/Cinch (NTSC or PAL)
- Y/C (s-video) (NTSC or PAL)
- Dual RCA stereo analog audio (with Dolby Surround encoding)
- Digital audio (IEC-958 Type II RCA coax (S/P DIF) or EIAJ CP-340 optical
(Toslink)). Raw digital audio (AC-3, MPEG-2, PCM, or optional DTS or SDDS)
requires an external decoder or an amplifier/receiver with built-in decoder.
(Note: The digital AC-3 audio output is not the same as the RF AC-3 output
on laserdisc players.)
Some players may have additional connections:
- Component analog video, NTSC or PAL (YUV: 3 RCA connectors, RGB: SCART
connector or 3 RCA)
- RF video output for connecting via channel 3 or 4 to TV without direct
input. (Panasonic DVD-A300, RCA 5500P)
- 6 RCA jacks for analog surround sound output. (Panasonic DVD-A300, RCA
5500P, Samsung DVD905)
- AC-3 RF output on combo LD/DVD players. LD AC-3 on RF output only, DVD
AC-3 on coax/optical outputs only. (Pioneer DVL-90, DVL-700)
Most of the DVD players with component outputs use YUV, which is
incompatible with RGB. European players with SCART connectors have RGB
outputs. YUV to RGB transcoders are rumored to be available for $200-$300,
but seem hard to track down. A $700 converter is available from avscience.
Note: The correct term for analog color-difference output is Y'Pb'Pr', not
Y'Cb'Cr' (which is digital, not analog). To simplify things, this FAQ uses
the term YUV in its generic sense to refer to color difference signals.
No DVD players have yet been announced with digital video outputs, but it's
expected that at some point digital output will be available using FireWire
(IEEE 1394) connectors (see <http://firewire.org>).
[3.2] How do I hook up a DVD player?
It depends on your audio/video system and your DVD player. Most DVD players
have 2 or 3 video hookup options and 3 audio hookup options. Choose the
option with the best quality (indicated below) that is supported by your
video and audio systems.
* Component video (best): Some U.S. and Japanese players have component
YUV video output in the form of 3 RCA or BNC connectors. Connectors may
be labelled YUV, color difference, YPbPr, or Y/B-Y/R-Y, and may be
colored green/blue/red. Some players have RGB component video output
via a 20-pin SCART connector or 3 RCA or BNC connectors labelled R/G/B.
Hook cables from the three video outputs of the player to the three
video inputs of the display, or a SCART cable from the player to the
display. Note: Connecting YUV to RGB will not work; a transcoder is
required. (Note: There is an unsubstantiated rumor that the Toshiba
SD-3006 component outputs have poor color conversion.)
* S-video (good): Almost all players have s-video output. Hook an s-video
cable from the player to the display (or to an A/V receiver that can
switch s-video). The round, 4-pin connectors may be labelled Y/C,
s-video, or S-VHS.
* Composite video (ok): All DVD players have standard RCA (Cinch)
baseband video connectors. Hook a standard video cable from the player
to the display (or to an A/V receiver ). The connectors are usually
yellow and may be labelled video, CVBS, composite, or baseband.
* RF video (worst): A few players have RF video output for televisions
with only an antenna connection. Connect a coax cable from the player
to the TV. A 300 ohm to 75 ohm adapter may be needed. Tune the TV to
channel 3 or 4 and set the switch on the back of the player to match.
Audio is supplied with the RF signal, but it's only mono, even on
stereo TVs. If you have a player without RF output, you can buy an RF
modulator (~$30) to hook up to an old TV with RF input only. You can
also route the video through a VCR, but this will usually cause picture
problems with any disc that's Macrovision protected (see 1.11).
Warning: If you connect your DVD player to a VCR and then to your TV, you
may have problems with discs that enable the player's Macrovision circuit.
This usually shows up as a repeated darkening and lightening of the picture.
Note: Most DVD players support widescreen signalling, which tells a
widescreen display what the aspect ratio is so that it can automatically
adjust. One standard (ITU-R BT.1119, used mostly in Europe) includes
information in a video scanline. Another standard, for Y/C connectors, adds
a 5V DC signal to the chroma line to designate a widescreen signal.
Unfortunately, some switchers and amps throw away the DC component instead
of passing it on to the TV.
Note: All DVD players have either a built-in Dolby Digital (AC-3) or MPEG-1
audio decoder, or both. MPEG-2 audio decoders are not currently available.
The decoder translates multi-channel audio into PCM audio. This is fed to
the digital output and also converted to analog for standard audio output.
* Digital audio (best): Almost all DVD players have digital audio outputs
for Dolby Digital (AC-3), MPEG-2 audio, PCM audio, DTS, and SDDS. For
DD AC-3 or MPEG-2, the appropriate decoder is required in the receiver
or as a separate audio processor. For PCM, a receiver with built-in DAC
or an outboard DAC is required. DTS and SDDS are not used on most
discs; they require the appropriate decoder in the receiver or a
separate audio processor. Some DVD players have coax connectors
(SP/DIF), some have fiber optic connectors (Toslink), and many have
both. Hook a 75-ohm coax cable or a fiber-optic cable between the
player and the receiver/processor. Some players provide separate
connectors for DD/MPEG and PCM. On others, you may need to select the
desired output format with the player setup menu or a switch on the
back of the player. Note: Make sure you use an audio quality cable; a
cheap RCA patch cable may cause the audio to not work. Note: connecting
to the AC-3/RF input will not work unless your reciever/decoder can
autoswitch, since DVD digital audio is not in RF format (see below).
* Component analog audio (good): Some players provide 6-channel analog
output from the internal Dolby Digital decoder. The digital-to-analog
conversion quality may be better or worse than an external decoder. A
receiver/amplifier with 6 inputs (or more than one amplifier) is
required; this type of unit is often called "Dolby Digital ready" or
"AC-3 ready." Unfortunately, in most cases you will be unable to adjust
the volume of individual channels. Hook 6 audio cables to the RCA
connectors on the player and to the matching connectors on the
receiver/amplifier. Some receivers require an adapter cable with a
DB-25 connector on one end and RCA connectors on the other.
* Stereo/surround analog audio (ok): All DVD players include two RCA
connectors for stereo output. Any disc with Dolby Digital or MPEG-2
audio will automatically be decoded and downmixed to Dolby Surround
output for connection to a regular stereo system or a Dolby
Surround/Pro Logic system. Connect two audio cables between the player
and a receiver, amplifier, or TV. Connectors may be labelled audio or
left/right; left is usually white, right is usually red.
* RF digital audio (LD only): Combination LD/DVD players include AC-3 RF
output for digital audio from laserdiscs. Hook a coax cable to the AC-3
RF input of the receiver/processor. Note: digital audio from DVDs does
not come out of the RF output, it comes out of the optical/coax
outputs. Analog audio from LDs will come out the stereo connectors, so
three separate audio hookups are required to cover all variations.
Note: Some people claim digital audio coax connections are better than
fiber-optic connections, others claim the opposite. In practice they're both
about the same, but there do seem to be more coax supporters.
[3.3] What are the sizes and capacities of DVD?
There are many variations on the DVD theme. There are two physical sizes: 12
cm (4.7 inches) and 8 cm (3.1 inches), both 1.2 mm thick. These are the same
form factors as CD. A DVD disc can be single-sided or double-sided. Each
side can have one or two layers of data. The amount of video a disc can hold
depends on how much audio accompanies it and how heavily the video and audio
are compressed. The oft-quoted figure of 133 minutes is apocryphal: a DVD
with only one audio track easily holds over 160 minutes, and a single layer
can actually hold up to 9 hours of video and audio if it's compressed to VHS
At a rough average rate of 4.7 Mbps (3.5 Mbps for video, 1.2 Mbps for three
5.1-channel soundtracks), a single-layer DVD holds around 135 minutes. A
two-hour movie with three soundtracks can average 5.2 Mbps. A dual-layer
disc can hold a two-hour movie at an average of 9.5 Mbps (very close to the
10.08 Mbps limit).
Capacities of DVD:
For reference, a CD-ROM holds about 650 MB (megabytes), which is 0.64 GB
(gigabytes) or 0.68 G bytes (billion bytes). In the list below, SS/DS means
single-/double-sided, SL/DL means single-/dual-layer, GB means gigabytes
(2^30), G means billions of bytes (10^9).
* DVD-5 (12cm, SS/SL): 4.38 GB (4.7 G) of data, over 2 hours of video
* DVD-9 (12cm, SS/DL): 7.95 GB (8.5 G), about 4 hours
* DVD-10 (12cm, DS/SL): 8.75 GB (9.4 G), about 4.5 hours
* DVD-18 (12cm, DS/DL): 15.90 GB (17 G), over 8 hours
* DVD-1? (8cm, SS/SL): 1.36 (1.4 G), about half an hour
* DVD-2? (8cm, SS/DL): 2.48 GB (2.7 G), about 1.3 hours
* DVD-3? (8cm, DS/SL): 2.72 GB (2.9 G), about 1.4 hours
* DVD-4? (8cm, DS/DL): 4.95 GB (5.3 G), about 2.5 hours
* DVD-R (12cm, SS/SL): 3.68 GB (3.95 G)
* DVD-R (12cm, DS/SL): 7.38 GB (7.9 G)
* DVD-R (8cm, SS/SL): 1.15 GB (1.23 G)
* DVD-R (8cm, DS/SL): 2.29 GB (2.46 G)
* DVD-RAM (12cm, SS/SL): 2.40 GB (2.58 G)
* DVD-RAM (12cm, DS/SL): 4.80 GB (5.16 G)
Tip: It takes about two gigabytes to store one hour of average video.
The increase in capacity from CD-ROM is due to: 1) smaller pit length
(~2.08x), 2) tighter tracks (~2.16x), 3) slightly larger data area (~1.02x),
4) more efficient channel bit modulation (~1.06x), 5) more efficient error
correction (~1.32x), 6) less sector overhead (~1.06x). Total increase for a
single layer is about 7 times a standard CD-ROM. There's a slightly
different explanation at <http://www.mpeg.org/MPEG/DVD/General/Gain.html>.
The capacity of a dual-layer disc is slightly less than double that of a
single-layer disc. The laser has to read "through" the outer layer to the
inner layer (a distance of 20 to 70 microns). To reduce inter-layer
crosstalk, the minimum pit length of both layers is increased from .4 um to
.44 um. In addition, the reference scanning velocity is slightly faster --
3.84 m/s, as opposed to 3.49 m/s for single layer discs. Bigger pits, spaced
farther apart, are easier to read correctly and are less susceptible to
jitter. Bigger pits and fewer of them mean reduced capacity per layer.
See 4.2 for details of recordable DVD (DVD-R and DVD-RAM).
[3.4] What are the video details?
DVD-Video is an application of DVD-ROM. DVD-Video is also an application of
MPEG-2. This means the DVD format defines subsets of these standards to be
applied in practice as DVD-Video. DVD-ROM can contain any desired digital
information, but DVD-Video is limited to certain data types designed for
A disc has one track (stream) of MPEG-2 constant bit rate (CBR) or variable
bit rate (VBR) compressed digital video. A restricted version of MPEG-2 Main
Profile at Main Level (MP@ML) is used. SP@ML is also supported. MPEG-1 CBR
and VBR video is also allowed. 525/60 (NTSC, 29.97 interlaced frames/sec)
and 625/50 (PAL, 25 interlaced frames/sec) video display systems are
expressly supported. Coded frame rates of 24 fps progressive from film, 25
fps interlaced from PAL video, and 29.97 fps interlaced from NTSC video are
typical. MPEG-2 progressive_sequence is not allowed, but interlaced
sequences can contain progressive pictures and progressive macroblocks. In
the case of 24 fps source, the encoder embeds MPEG-2 repeat_first_field
flags into the video stream to make the decoder either perform 3-2 pulldown
for 60 (59.94) Hz displays or 2-2 pulldown (with 4% speedup) for 50 Hz
displays. In other words, the player doesn't really "know" what the encoded
rate is, it simply follows the MPEG-2 encoder's instructions to produce the
predetermined display rate of 25 fps or 29.97 fps. (No current players
convert from PAL to NTSC or NTSC to PAL. See 1.19.) It's interesting to note
that even interlaced source video is usually encoded as
progressive-structured MPEG pictures, with interlaced field-encoded
macroblocks used only when needed for motion. On a computer, which is not
tied to the display refresh rate, the repeat_first_field flags can be mostly
ignored and the video can be shown as progressive frames at the original
rate. Computers can also improve the quality of interlaced source by
doubling fields and displaying them as progressive frames at twice the
normal rate. Most film source is encoded progressive; most video sources are
encoded interlaced. These may be mixed on the same disc, such as an
interlaced logo followed by a progressive movie.
See the MPEG page <http://www.mpeg.org> for more information on MPEG-2
Picture dimensions are max 720x480 (29.97 frames/sec) or 720x576 (25
frames/sec). Pictures are subsampled from 4:2:2 ITU-R 601 down to 4:2:0,
allocating an average of 12 bits/pixel. (Color depth is still 24 bits, since
color samples are shared across 4 pixels.) The uncompressed source is
124.416 Mbps for video source (720x480x12x30 or 720x576x12x25), or either
99.533 or 119.439 Mbps for film source (720x480x12x24 or 720x576x12x24).
Using the traditional (and rather subjective) television measurement of
"lines of horizontal resolution" DVD can have 540 lines on a standard TV
(720/(4/3)) and 405 on a widescreen TV (720/(16/9)). In practice, most DVD
players provide about 500 lines because of filtering. VHS has about 230 (172
w/s) lines and laserdisc has about 425 (318 w/s).
Different players use different numbers of bits for the video
digital-to-analog converter. (Sony and Toshiba use 10 bits, Pioneer and
Panasonic use 9 bits.) This has nothing to do with the MPEG decoding
process, since each original component signal is limited to 8 bits per
sample. More bits in the player provide more "headroom" and more signal
levels during digital-to-analog conversion, which can help produce a better
Maximum video bitrate is 9.8 Mbps. The "average" bitrate is 3.5 but depends
entirely on the length, quality, amount of audio, etc. This is a 36:1
reduction from uncompressed 124 Mbps (or a 28:1 reduction from 100 Mbps film
source). Raw channel data is read off the disc at a constant 26.16 Mbps.
After 8/16 demodulation it's down to 13.08 Mbps. After error correction the
user data stream goes into the track buffer at a constant 11.08 Mbps. The
track buffer feeds system stream data out at a variable rate of up to 10.08
Mbps. After system overhead, the maximum rate of combined elementary streams
(audio + video + subpicture) is 10.08. MPEG-1 video rate is limited to 1.856
Mbps with a typical rate of 1.15 Mbps.
Still frames (encoded as MPEG-2 I-frames) are supported and can be displayed
for a specific amount of time or indefinitely. These are generally used for
menus. Still frames can be accompanied by audio.
A disc also can have up to 32 subpicture streams that overlay the video for
subtitles, captions for the hard of hearing, captions for children, karaoke,
menus, simple animation, etc. These are full-screen, run-length-encoded
bitmaps limited to four pixel types. For each group of subpictures, four
colors are selected from a palette of 16 (from the YCrCb gamut), and four
contrast values are selected out of 16 levels from transparent to opaque.
Subpicture display command sequences can be used to create effects such as
scroll, move, color/highlight, and fade. The maximum subpicture data rate is
3.36 Mbps, with a maximum size per frame of 53220 bytes.
[3.5] How do the aspect ratios work?
Video can be stored on a DVD in 4:3 format (standard TV shape) or 16:9
(widescreen). The 16:9 format is "anamorphic," meaning the picture is
squeezed horizontally to fit a 4:3 rectangle then unsqueezed during
playback. DVD players can output video in four different ways:
* full frame (4:3 video for 4:3 display)
* letterbox (16:9 video for 4:3 display)
* pan & scan (16:9 video for 4:3 display)
* widescreen (16:9 video for 16:9 display)
Video stored in 4:3 format is not changed by the player. It will appear
normally on a standard 4:3 display. Widescreen systems will either enlarge
it or add black bars to the sides. 4:3 video may have been formatted in
various ways before being transferred to DVD. For example, it may have been
letterboxed to hold video with a wider shape. Or it may have been panned &
scanned from film composed for a wider theatrical presentation. All
formatting done to the video prior to it being stored on the disc is
transparent to the player. It merely reproduces the signal in standard form.
Anamorphic (16:9) video can be displayed on widescreen equipment, which
stretches the video back out to its original width. If anamorphic video is
shown on a standard 4:3 display, people will look like they have been on a
crash diet. Widescreen mode is complicated because most movies today are
shot with a "soft matte." (The cinematographer has two sets of frame marks
in her viewfinder, one for 1.33 (4:3) and one for 1.85, so she can allow for
both formats). A few movies are even wider, such as the 2.35 ratio of
Panavision. Since most movies are wider than 1.78 (16:9), one of at least 4
methods must be used during transfer to make it fit the 1.78 rectangle: 1)
add additional thin black bars to the top and bottom; 2) include a small
amount of extra picture at the top and bottom from the soft matte area; 3)
crop the sides; 4) pan & scan with a 1.78 window. With the first two
methods, the difference between 1.85 and 1.78 is so small that the letterbox
bars or extra picture are hidden in the overscan area of most televisions.
Nevertheless, and especially with 2.35 movies, many DVD producers put 16:9
source on one side (or layer) of the disc and 4:3 source on the other. This
way the full-frame version of the film can be used for a horizontal and
vertical pan & scan & zoom process with no letterbox bars and no reduction
Anamorphic video can also be converted by the player for display on standard
4:3 TVs in letterbox or pan & scan form. The conversion options available
for each disc are determined by the producer of the disc. So far no discs
have been released with auto letterbox option (partly because equipment for
storing the picture shift information is not widely available).
For automatic letterbox mode, the player creates black bars at the top and
the bottom of the picture (60 lines each for NTSC, 72 for PAL). This leaves
3/4 of the height remaining, creating a shorter but wider rectangle. In
order to fit this shorter rectangle, the picture is squeezed vertically
using a "letterbox filter" that combines every 4 lines into 3. This
compensates for the original horizontal squeezing, resulting in the movie
being shown in its full width. The vertical resolution is reduced from 480
lines to 360.
For automatic pan & scan mode, the video is unsqueezed to 16:9 and a portion
of the image is shown at full height on a 4:3 screen by following a "center
of interest" offset that's encoded in the video stream according to the
preferences of the people who transferred the film to video. The pan & scan
"window" is 75% of the full width, which reduces the horizontal pixels from
720 to 540. The pan & scan window can only travel laterally. This does not
duplicate a true pan & scan process in which the window can also travel up
and down and zoom in and out. Therefore, most DVD producers choose to put a
separate pan & scan version on the disc in addition to the widescreen
Anamorphosis causes no problems with line doublers, which simply double the
lines before they are stretched out by the widescreen display.
For anamorphic video, the pixels are fatter. Different pixel aspect ratios
(none of them square) are used for each aspect ratio and resolution.
720-pixel and 704-pixel sizes have the same aspect ratio because the first
includes overscan. Note that "conventional" values of 1.0950 and 0.9157 are
for height/width (and are tweaked to match scanning rates). The table below
uses less-confusing width/height values (y/x * h/w).
704x480 704x486 352x480 352x576
4:3 0.909 1.091 1.818 2.182
16:9 1.212 1.455 2.424 2.909
Playback of widescreen material can be restricted. Programs can be marked
for the following display modes:
- 4:3 full frame
- 4:3 LB (for automatically setting letterbox expand mode on widescreen TV)
- 16:9 LB only (player not allowed to pan & scan on 4:3 TV)
- 16:9 PS only (player not allowed to letterbox on 4:3 TV)
- 16:9 LB or PS (viewer can select pan & scan or letterbox on 4:3 TV)
[3.6] What are the audio details?
The DVD-Audio format is not yet specified. The International Steering
Committee announced it expects to have a final draft specification by
December 1997. This means they won't really have one until about mid 1998,
and DVD-Audio products may show up around 1999 at the earliest.
The following details are for audio tracks on DVD-Video. Some DVD
manufacturers such as Pioneer are developing audio-only players using the
A disc can have up to 8 audio tracks (streams). Each track can be in one of
* Dolby Digital (formerly AC-3): 1 to 5.1 channels
* MPEG-2 audio: 1 to 5.1 or 7.1 channels
* PCM: 1 to 8 channels.
Two additional optional formats are provided: DTS and SDDS. Both require
external decoders and are not supported by all players.
The ".1" refers to a low-frequency effects (LFE) channel that connects to a
subwoofer. This channel carries an emphasized bass audio signal.
Linear PCM is uncompressed (lossless) digital audio, the same format used on
CDs and most studio masters. It can be sampled at 48 or 96 kHz with 16, 20,
or 24 bits/sample. (Audio CD is limited to 44.1 kHz at 16 bits.) There can
be from 1 to 8 channels. The maximum bitrate is 6.144 Mbps, which limits
sample rates and bit sizes with 5 or more channels. It's generally felt that
the 96 dB dynamic range of 16 bits or even the 120 dB range of 20 bits
combined with a frequency response of up to 22,000 Hz from 48 kHz sampling
is adequate for high-fidelity sound reproduction. However, additional bits
and higher sampling rates are useful in studio work, noise shaping, advanced
digital processing, and three-dimensional sound field reproduction. DVD
players are required to support all the variations of LPCM, but some of them
may subsample 96 kHz down to 48 kHz, and some may not use all 20 or 24 bits.
The signal provded on the digital output for external digital-to-analog
converters may be limited to less than 96 kHz or less than 24 bits.
Dolby Digital is multi-channel digital audio, compressed using AC-3 coding
technology from original PCM with a sample rate of 48 kHz at 16 bits. The
bitrate is 64 kbps to 448 kbps, with 384 being the normal rate for 5.1
channels and 192 being the normal rate for stereo (with or without surround
encoding). The channel combinations are (front/surround): 1/0, 1+1/0 (dual
mono), 2/0, 3/0, 2/1, 3/1, 2/2, and 3/2. The LFE channel is optional with
all 8 combinations. For details see ATSC document A/52
<http://www.atsc.org/document.html>. Dolby Digital is the format used for
audio tracks on almost all DVDs.
MPEG audio is multi-channel digital audio, compressed from original PCM
format with sample rate of 48 kHz at 16 bits. Both MPEG-1 and MPEG-2 formats
are supported. The variable bitrate is 32 kbps to 912 kbps, with 384 being
the normal average rate. MPEG-1 is limited to 384 kbps. Channel combinations
are (front/surround): 1/0, 2/0, 2/1, 2/2, 3/0, 3/1, 3/2, and 5/2. The LFE
channel is optional with all combinations. The 7.1 channel format adds
left-center and right-center channels, but will probably be rare for home
use. MPEG-2 surround channels are in an extension stream matrixed onto the
MPEG-1 stereo channels, which makes MPEG-2 audio backwards compatible with
MPEG-1 hardware (an MPEG-1 system will only see the two stereo channels.)
MPEG Layer III (MP3) and MPEG-2 AAC (aka NBC, aka unmatrix) are not
supported by the DVD-Video standard.
DTS (Digital Theater Sound) is an optional multi-channel (5.1) digital audio
format, compressed from PCM at 48 kHz. The data rate is from 64 kbps to 1536
kbps. Channel combinations are (front/surround): 1/0, 2/0, 3/0, 2/1, 2/2,
3/2. The LFE channel is optional with all 6 combinations. The DVD standard
includes an audio stream format reserved for DTS, but first-generation
players ignore it. A few demo discs were created by using a "fake" PCM track
containing DTS audio (this is the same technique used with CDs and
laserdiscs). These are the only DTS DVD discs that work on all players. New
DTS-compatible players and official DTS discs using the proper DTS audio
stream will arrive in early or mid 1998. Some manufacturers may provide
upgrades to make existing discs comaptible with DTS discs. According to DTS,
existing DTS decoders will work with DTS DVDs. Note: All DVD players can
play DTS audio CDs.
SDDS (Sony Dynamic Digital Sound) is an optional multi-channel (5.1 or 7.1)
digital audio format, compressed from PCM at 48 kHz. The data rate can go up
to 1280 kbps. Sony has not announced any plans to support SDDS on DVD.
THX (Tomlinson Holman Experiment) is not an audio format. It's simply an
additional set of processes applied by THX-certified surround sound
amplifiers. "THX 4.0" processing is added to Dolby Pro Logic: crossover
sends bass from front channels to subwoofer; re-equalization on front
channels; timbre matching on rear channels; decorrelation of rear channels;
bass curve that emphasizes low frequencies. "THX 5.1" processing is added to
Dolby Digital and improves on 4.0: rear speakers are now full range, so
crossover sends bass from both front and rear to subwoofer; decorrelation is
turned on automatically when rear channels have the same audio, but not
during split-surround effects, which don't need to be decorrelated.
Discs containing 525/60 video (NTSC) must use PCM or Dolby Digital on at
least one track. Discs containing 625/50 video (PAL/SECAM) must use PCM or
MPEG audio or Dolby Digital on at least one track. Additional tracks may be
in any format. A few first-generation players, such as those made by
Matsushita, can't output MPEG-2 audio to external decoders.
The original spec required either MPEG audio or PCM on 625/50 discs. There
was a brief scuffle led by Philips when early discs came out with only
two-channel MPEG and multichannel Dolby Digital, but the DVD Forum clarified
in May 1997 that only stereo MPEG audio was mandatory for 625/50 discs. In
December 1997 the lack of MPEG-2 encoders (and decoders) was a big enough
problem that the spec was revised to allow Dolby Digital as the only audio
track on 625/50 discs.
For stereo output (analog or digital), all players have a built-in 2-channel
Dolby Digital decoder that downmixes from 5.1 channels (if present on the
disc) to Dolby Surround stereo (i.e., 5 channels are matrixed into 2
channels to be decoded to 4 by an external Dolby Pro Logic processor). PAL
players also have an MPEG or MPEG-2 decoder. Both Dolby Digital and MPEG-2
support 2-channel Dolby Surround as the source in cases where the disc
producer can't or doesn't want to remix the original onto discrete channels.
This means that a DVD labelled as having Dolby Digital sound may only use
the L/R channels for surround or "plain" stereo. Even movies with old
monophonic soundtracks may use Dolby Digital -- but only 1 or 2 channels.
Sony players can optionally downmix to non-surround stereo.
The Dolby Digital downmix process does not usually include the LFE channel
and may compress the dynamic range in order to improve dialog audibility and
keep the sound from becoming "muddy" on average home audio systems. This can
result in reduced sound quality on high-end audio systems. Some players have
the option to turn off the dynamic range compression. The downmix is
auditioned when the disc is prepared, and if the result is not acceptable
the audio may be tweaked or a separate L/R Dolby Surround track may be
added. Experience has shown that minor tweaking is sometimes required to
make the dialog more audible within the limited dynamic range of a home
stereo system, but that a separate track is not usually necessary. If
surround audio is important to you, you will hear significantly better
results from multichannel discs if you have a Dolby Digital system.
All five audio formats support karaoke mode, which has two channels for
stereo (L and R) plus an optional guide melody channel (M) and two optional
vocal channels (V1 and V2).
A DVD-5 with only one surround stereo audio stream (at 192 kbps) can hold
over 55 hours of audio. A DVD-18 can hold over 200 hours.
Many people complain that the audio level from DVD players is too low. In
truth the audio level is too high on everything else. Movie soundtracks are
extremely dynamic, ranging from near silence to intense explosions. In order
to support an increased dynamic range and hit peaks (near the 2V RMS limit)
without distortion, the average sound volume must be lower. This is why the
line level from DVD players is lower than from almost all other sources. And
so far, unlike on CDs and LDs, the level is much more consistent between
[3.7] How do the interactive features work?
DVD-Video players (and software DVD-Video navigators) support a command set
that provides rudimentary interactivity. The main feature is menus, which
are present on almost all discs to allow content selection and feature
control. Each menu has a still-frame graphic and up to 36 highlightable,
rectangular "buttons" (only 12 if widescreen, letterbox, and pan & scan
modes are used). Remote control units have four arrow keys for selecting
onscreen buttons, plus numeric keys, select key, menu key, and return key.
Additional remote functions may include freeze, step, slow, fast, scan,
next, previous, audio select, subtitle select, camera angle select, play
mode select, search to program, search to part of title (chapter), search to
time, and search to camera angle. Any of these features can be disabled by
the producer of the disc.
Additional features of the command set include simple math (add, subtract,
multiply, divide, modulo, random), bitwise and, bitwise or, bitwise xor,
plus comparisons (equal, greater than, etc.), and register loading, moving,
and swapping. There are 24 system registers for information such as language
code, audio and subpicture settings, and parental level. There are 16
general registers for command use. A countdown timer is also provided.
Commands can branch or jump to other commands. Commands can also control
player settings, jump to different parts of the disc, and control
presentation of audio, video, subpicture, camera angles, etc.
DVD-V content is broken into "titles" (movies or albums), and "parts of
titles" (chapters or songs). Titles are made up of "cells" linked together
by one or more "program chains" (PGC). A PGC can be defined as sequential
play, random play (may repeat), or shuffle play (random order but no
repeats). Individual cells may be used by more than one PGC, which is how
parental management and seamless branching are accomplished: different PGCs
define different sequences through mostly the same material.
Additional material for camera angles and seamless branching is interleaved
together in small chunks. The player jumps from chunk to chunk, skipping
over unused angles or branches, to stitch together the seamless video. Since
angles are stored separately, they have no direct effect on the bitrate but
they do affect the playing time. Adding 1 camera angle for a program roughly
doubles the amount of space it requires (and cuts the playing time in half).
 DVD and computers
[4.1] Can I play DVD movies on my computer?
Only if your computer has the right stuff. In addition to a DVD-ROM drive,
you must have extra hardware to decode MPEG-2 video and Dolby
Digital/MPEG-2/PCM audio. The computer operating system or playback system
must support regional codes and be licensed to decrypt copy-protected
movies. You may also need software that can read the MicroUDF format used to
store DVD data files and interpret the DVD control codes. It's estimated
that 10-30% of new computers with DVD-ROM drives will include decoder
hardware, and that most of the remaining DVD-ROM computers will include
movie playback software. Hardware upgrade kits can also be purchased
separately for $500 to $1,000. (OEM price for playback hardware is about
$200.) Creative and Hi-Val upgrade kits require a 133 Mhz Pentium. E4's
CoolDVD upgrade kit requires a 120 MHz 604 PowerPC or better.
Note: The recently released QuickTime MPEG Extension for MacOS is for MPEG-1
only and does NOT play MPEG-2 DVD-Video.
Some DVD-Videos and many DVD-ROMs will use video encoded using MPEG-1
instead of MPEG-2. Many existing computers have MPEG-1 hardware built in or
are able to decode MPEG-1 with software.
CompCore Multimedia and Mediamatics make software to play DVD-Video movies
(SoftDVD, DVD Express). Both require at least a 233 MHz Pentium MMX with AGP
and an IDE/SCSI DVD-ROM drive with bus mastering DMA support to achieve
about 20 frame/sec film rates (or better than 300 MHz for 30 frame/sec
video), and can decrypt copy-protected movies (see 1.11). Oak's software
requires hardware support. These software "navigators" support most
DVD-Video features (menus, subpictures, etc.) and can emulate a DVD-Video
CompCore, Mediamatics, and Oak Technology have defined standards to allow
certain MPEG decoding tasks to be performed by hardware on a video card and
the remainder by software. Video graphics controllers with this feature are
being called "DVD MPEG-2 accelerated." (The Mediamatics standard is called
If you have at least a 433 MHz Alpha workstation you'll be able to play DVD
movies at full 30 fps in software.
[4.2] What are the features and speeds of DVD-ROM drives?
Most DVD-ROM drives have a seek time of 150-200 ms, access time of 200-250
ms, and data transfer rate of 1.3 MB/s (11.08*10^6/8/2^20) with burst
transfer rates of up to 12 MB/s or higher. The data transfer rate from
DVD-ROM discs is roughly equivalent to a 9x CD-ROM drive. DVD spin rate is
about 3 times faster than CD, so a few DVD-ROM drives read CD-ROM data at 3x
speed, but most are 12x or faster. 2x and 3x DVD-ROM drives are already in
the works. New 2x DVD-ROM drives (Hitachi, Creative) read CD-ROMs at 20x and
Connectivity is similar to that of CD-ROM drives: EIDE (ATAPI), SCSI-2, etc.
All DVD-ROM drives have audio connections for playing audio CDs. No DVD-ROM
drives have been announced with DVD audio or video outputs (which would
require internal audio/video decoding hardware).
DVD-ROMs use a MicroUDF/ISO 9660 bridge file system. The OSTA UDF file
system will eventually replace the ISO 9660 system of CD-ROMs, but the
bridge format provides backwards compatibility until operating systems
[4.3] What about recordable DVD: DVD-R, DVD-RAM, DVD+RW, and DVD-ER?
There are two recordable versions of DVD-ROM: DVD-R (record once) and
DVD-RAM (erase and record many times), with capacities of 3.95 and 2.58
billion bytes. Final versions of both specifications were published August
1997. DVD-R and DVD-RAM are not currently usable for home video recording
DVD-R uses organic dye polymer technology like CD-R and is compatible with
almost all DVD drives. The technology will improve to support 4.7 billion
bytes by 1999 or 2000, which is crucial for desktop DVD-ROM and DVD-Video
DVD-RAM uses phase-change (PD) technology and is not compatible with current
drives (because of defect management, reflectivity differences, and minor
format differences). A wobbled groove is used to provide clocking data, with
marks written in both the groove and the land between grooves. The grooves
and pre-embossed sector headers are molded into the disc during
manufacturing. New DVD-ROM drives that can read DVD-RAM discs are expected
in early 1998. Single-sided DVD-RAM discs come with or without cartridges.
There are two types of cartridges: type 1 is sealed, type 2 allows the disc
to be removed. Double-sided DVD-RAM discs will be available in sealed
cartridges only. Cartridge dimensions are 124.6mm x 135.5mm x 8.0mm. Future
DVD-RAM discs may use a contrast enhancement layer and a thermal buffer
layer to achieve higher density. Hitachi has announced reaching 4.7 billion
bytes by reducing mark size from 0.41/0.43 microns to 0.28/0.30 microns and
track pitch from 0.74 microns to 0.59 microns.
Pioneer released DVD-R drives in October 1997 for $17,000. This price could
drop within a few years to less than $5,000. Initial price for blank DVD-Rs
is $50. DVD-RAM drives will be introduced for less than $1000, with blank
discs at about $30 for single-sided and $45 for double-sided. Disc prices
for both DVD-R and DVD-RAM will drop quickly, but DVD-R discs will probably
be cheaper in the long run. Toshiba, Pioneer, and Hitachi expect DVD-RAM to
be available in early 1998, which means it will probably appear in the
middle of 1998.
The primary advantages of DVD-R drives, which are used primarily for DVD
production, are higher capacity and compatibility with all DVD players and
drives. Matsushita, Taiyo Yuden, Mitsubishi, and Hitachi Maxell have all
announced 4.7-billion-byte DVD-R formats. These are not competing DVD-R
formats, merely manufacturing advances that allow higher density. The discs
may not be readable in first-generation drives and players, but will be
supported by all future DVD drives.
DVD Phase-Change Rewritable, called DVD+RW without the blessing of the DVD
Forum, is a competing erasable format announced by Philips, Sony,
Hewlett-Packard and others based on CD-RW technology. DVD+RW drives will
read DVD-ROMs and CDs, but are not compatible with DVD-RAM. Minor changes to
DVD-ROM drives will allow them to read DVD+RW discs. DVD+RW, which holds 2.8
gigabytes (3G) uses phase-change technology with wobbled groove and either
CLV format for sequential video access (read at CAV speeds by drive) or CAV
format for random access. DVD+RW will not be ready for production until late
1998 at the earliest, and its backers claim it will be used only for
computer data, not home video. Second-generation DVD+RW drives will write
CD-Rs and CD-RWs.
DVD-R/W is yet another announced phase-change erasable format. Developed by
Pioneer based on DVD-R, DVD-R/W uses the same track pitch, mark length, and
rotation control, and should be playable in first-generation DVD drives and
players. DVD-R/W uses groove recording with address info on land areas for
synchronization at write time (land data is unnecessary during reading).
Capacity will probably be 3.95 billion bytes, later expanded to 4.7.
Other upcoming potential competitors to DVD-RAM include ASMO (formerly MO7),
which holds 5 to 6 billion bytes, and NEC's MMVF (Multimedia Video Format),
which holds 5.5 billion bytes. Both are expected to read DVD-ROM (and DVD-R)
but not DVD-RAM or DVD+RW.
 DVD production
[5.1] How much does it cost to produce a DVD? Isn't DVD much more expensive
than videotape, laserdisc, and CD-ROM?
Videotape, laserdisc, and CD-ROM can't be compared to DVD in a
straightforward manner. There are basically three stages of costs:
production, pre-mastering (authoring, encoding, and formatting), and
DVD production costs are not much higher than for existing media, unless the
extra features of DVD-Video such as multiple sound tracks, camera angles,
etc. are employed.
Pre-mastering costs are proportionately the most expensive part of DVD.
Video and audio must be encoded, menus and control information have to be
authored and encoded, it all has to be multiplexed into a single data
stream, and finally encoded in low level format. Warner's charges for
compression are $120/min for video, $20/min for audio, $6/min for subtitles,
plus formatting and testing at about $30/min. A ballpark estimate for
producing a two-hour DVD movie is about $30,000. If you want to do
pre-mastering yourself, authoring and encoding systems can be purchased from
$100,000 to over $2 million. These prices will drop very rapidly in the next
few years to where DVDs can be produced on desktop computer systems using
additional hardware costing less than $20,000.
Videotapes don't really have a mastering cost, and they run about $2.40 for
replication. CDs cost about $1,000 to master and $0.50 to replicate.
Laserdiscs cost about $3,000 to master and about $8 to replicate. DVDs
currently cost about $3000 to master and about $1.80 to replicate. Since DVD
production is based mostly on the same equipment used for CD production,
mastering and replication costs will quickly drop to CD levels.
Pre-mastering costs are mostly for authoring systems and encoding systems
which cost hundreds of thousands of dollars, but these too will get much
cheaper in the next few years.
Double-sided or dual-layer discs cost only slightly more to replicate, since
all that's required is stamping data on the second substrate (and using
transparent glue for dual layers). Double-sided/dual-layer discs are more
[5.2] What DVD authoring systems are available and how much do they cost?
* DVD Creator (encoding) and Scenarist DVD (authoring) from Sonic
Solutions and Daikin. $180,000 (full cost is about $250,000 with hard
disks, DLT drive, Macintosh PowerPC (for Creator), SGI (for Scenarist),
etc.). Sonic also makes DVD Creator Workstation, a $100,000 system that
runs on a single Macintosh.
* DVD-Fab from Optibase. Includes Optibase MPEG Fusion MPEG-2 encoder.
Runs under Windows NT 4.0.
* DVD-Professional SL from Minerva (includes Publisher 300 and Minerva
Studio). $100,000. Windows NT. <http://www.minervasys.com>
* DVD-RICH from Gunzameory. $30,000, requires Windows 95 on 166-MHz
* ZX-2000 from Zapex Technologies. MPEG-2 video encoding, MPEG/DD audio
* InnovaCom, Panasonic, JVC, Toshiba, and Pioneer all have authoring
systems under development but nothing available at the moment.
Authoring can also be done by many service bureaus (see below) for around
[5.3] Who can produce a DVD for me?
* [A] All Post (CA), 818-556-5756.
* [A] AVM Dialog AB (Goteborg, Sweden)
* [A] Cinram POP DVD Center (Santa Monica, CA)
* [R] Cinram, Inc. (Richmond, IN)
* [A] CKS|Pictures (CA & NY), <email@example.com> 408-342-5009.
* [A] Complete Post (CA).
* [AS] CRUSH Digital Video (NY), <info@CrushDV.com> 212-965-1501.
* [A] D2 Productions (CA), <http://www.d2prod.com> 818-576-8113.
* [A] dHouse (CA), <http://www.d-House.com>.
* [A] Digital Video Compression Corporation (CA), <http://www.dvcc.com>
* [A] Digital Video Mastering (Sydney, Australia)
* [R] Disc Manufacturing Inc. (AL & CA), <http://www.discmfg.com>
* [A] Digital Media Group (Amsterdam, The Netherlands)
* [AS] EDS Digital Studios (CA), 213-850-1165.
* [A] Electric Switch (London), 44-0-131-555-6055 <firstname.lastname@example.org>
* [A] Film- und Videotechnik B. Gurtler (Munchen, Germany)
* [A] Hecker & Schneider GmbH (Dortmund, Germany)
* [A] IBM InteractiveMedia (GA), <email@example.com> 770-835-7193.
* [R] Imation (formerly 3M) (WI), 612-704-4898.
* [AS] Intel (OR),
* [R] JVC Disc America (CA), 310-274-2221.
* [AS] KAO Infosystems (CA), <www.kaoinfo.com> 510-657-8425.
* [A] k-kontor (Hamburg) kommunikations (Hamburg, Germany)
* [AR] Kao (ON), 800-871-MPEG.
* [AR] Kao Infosystems (Fremont, CA), 800-525-6575
* [AR] LaserPacific (CA), <http://www.laserpacific.com> 213-462-6266.
* [AR] Memory-Tech Corporation (Tokyo, Japan).
* [R] Metatec (OH), <http://www.metatec.com> 614-761-2000.
* [AS] NB Digital Solutions (MD), <http://www.nbeng.com/dvd.htm>
* [R] Nimbus Manufacturing. <http://www.nimbuscd.com> 804-985-1100.
* [A] NOB Interactive (Netherlands) <http://www.nob.nl>
* [AS] One(UK) Ltd. (London, UK) <http://www.one-uk.com> +44-171-316-7800
(Daikin Authorized Expertise Center for Europe)
* [R] Optical Disc Corporation, 310-946-3050. (LaserWave DirectCut DVD
recorder for creating single copies.)
* [R] Optical Disc Media (CA)
* [A] Pacific Coast Sound Works (CA), 213-655-4771.
* [R] Pacific Mirror Image (Melbourne, Australia)
* [A] Pacific Ocean Post Sound (CA), audio only, 310-458-9192.
* [A] Pacific Video Resources (CA), <http://www.pvr.com> 415-864-5679.
* [A] Paris Media System (Paris, France).
* [A] Pioneer France (Nanterre, France).
* [R] Pioneer Video Manufacturing, Inc.,
* [AR] PolyGram Manufacturing & Distribution Center (Langenhagen,
Germany), +49 511 972 1486.
* [AS] Rainmaker Interactive (BC), <http://www.rainmaker.com>
* [AR] RiTEK Corporation (Taiwan)
* [A] Sunset Post (CA), <http://www.sunsetpost.com> 818-956-7912.
* [A] Stimulus (Calgary, Alberta)
* [A] Sync Sound (NY), 212-246-5580 (5.1 audio).
* [R] Technicolor, <firstname.lastname@example.org> 800-732-4555.
* [AS] Valkieser Solutions (Hilversum, Netherlands),
* [ASR] Warner Advanced Media Operations, 717-383-3291.
* [A] Zapex
[A] Authoring (including compression and premastering).
[R] Replication (mastering and/or one-offs).
[S] Use Daikin Scenarist authoring system.
See Robert's DVD Info page <http://www.unik.no/~robert/hifi/dvd/> for more
[5.4] Who can test or verify DVDs?
* Entertainment Media Services (Time Warner) (CA), <email@example.com>
* CD Associates (CA), <http://www.cdassociates.com> (714) 733-8580
[6.1] Who invented DVD and who owns it? Whom to contact for specifications
DVD is the work of Toshiba, Matsushita, Philips, Sony, and others. There
were originally two next-generation standards for DVD. The MMCD format was
backed Sony, Philips, and others. The competing SD format was backed by
Toshiba, Time Warner, and others. A group of computer companies led by IBM
insisted that the DVD proponents agree on single standard. The combined DVD
format was announced in September of 1995, avoiding a confusing and costly
repeat of the VHS vs. BetaMax videotape battle (or the quadraphonic sound
battle of the 1970s).
No single company "owns" DVD. The standard was developed by a consortium of
10 companies: Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony,
Thomson, Time Warner, and Toshiba. Working groups with representatives from
many other companies also contributed. In May 1997, the Consortium was
replaced by the DVD Forum, which is open to all companies. Visit Robert's
DVD Info page <http://www.unik.no/~robert/hifi/dvd/> for links to Web pages
of companies working with DVD.)
The official DVD specification books are available from Toshiba after
signing a nondisclosure agreement and paying a $5000 fee. Contact Toshiba
DVD Products 1-1 Shibaru 1-Chome, Minato-ku, Tokyo 105-01, Japan,
81-3-3457-2473, fax 81-3-5444-9401.
Any company making DVD products must license the patented technology from a
Philips/Pioneer/Sony pool, a Hitachi/Matsushita/Mitsubishi/Time
Warner/Toshiba/Victor pool, and from Thomson. Total royalties are about 5%
for a DVD-Video player, $6 for a DVD-ROM drive and decoder, and 10 cents for
a DVD disc. Matsushita licenses the CSS encryption technology free of
charge. Macrovision licenses its analog anti-recording technology free of
charge to hardware makers, but charges a per-copy royalty to content
publishers. The DVD format and logo must also be licensed; contact Toshiba
DVD Business Promotion and Support: 81-3-5444-9580, fax 81-3-5444-9430. An
MPEG-2 patent license is also required, from MPEG LA (Licensing
Adminstrator). Cost is $4 for a DVD player or decoder card and 4 cents for
each DVD disc. Contact MPEG LA for more info: <http://www.mpegla.com>.
[6.2] Who is making or supporting DVD products?
The following companies have made official statements of products
specifically designed for the DVD format.
* Akai: DVD-Video player
* Alpine: DVD-ROM car navigation system
* Altec Lansing: DVD audio technology
* Clarion: DVD-ROM car navigation system
* Denon: DVD-Video player
* Faroudja: DVD-Video player
* Fisher: DVD-Video player
* Harman Kardon: DVD-Video player
* Hitachi: DVD-Video player
* Hyundai: DVD-Video player
* Innovacom: PC/TV with DVD support
* JVC (Victor): DVD-Video players
* Kenwood: DVD-Video player
* LG Electronics (GoldStar): DVD-Video players
* Matsushita (Panasonic/National/Technics/Quasar): DVD-Video players,
DVD-ROM car navigation system
* Meridian: DVD-Video player
* Mitsubishi: DVD-Video players
* NEC: DVD-RAM video camera
* Onkyo: DVD-Video player
* Philips (Magnavox/Marantz/Norelco): DVD-Video player
* Pioneer: DVD-Video players, DVD-ROM car navigation system
* Runco: DVD-video player and changer
* Samsung: DVD-Video players
* Sanyo: DVD-Video player
* Sharp: DVD-Video player
* Sony: DVD-Video players
* Thomson (RCA/GE/Proscan/Ferguson/Nordmende/Telefunken/Saba/Brandt):
* Toshiba: DVD-Video players
* Yamaha: DVD-Video player
* Zenith: DVD-Video player
Studios, video publishers, and distributors:
* Aftermath Media/Funsoft Holdings (interactive movie)
* All Day Entertainment
* Anchor Bay
* BMG (Sonopress)
* Cecchi Gori
* Columbia TriStar (Sony) (37 titles in 1997)
* Concorde Video (12 Monkeys, German)
* Criterion (6 titles beginning in Feb 1998)
* Delos International (mostly audio)
* Digital Disc Entertainment
* Digital Leisure (formerly ReadySoft) (Dragon's Lair, Space Ace)
* Disney (Buena Vista Home Video, Dimension, Hollywood, Miramax,
* DreamWorks SKG
* DVD International (distributor)
* Elite Entertainment
* Fox Lorber
* Gainax (anime)
* HBO (Warner)
* Image Entertainment (distributor)
* Impressive (adult)
* Laserdisc Entertainment (adult)
* LIVE Entertainment (Warner)
* Master Tone
* Metro Global Media (adult)
* MGM/UA (Warner)
* Microsoft (Encarta DVD-ROM)
* Mill Reef (Earthlight)
* New Line (Warner)
* Orion Pictures (distributed by Image)
* Paramount Home Video (Divx only)
* Pioneer Entertainment (distributor)
* Polygram (Philips partner)
* Pony Canyon (Japan)
* Pro7 Home Enterntainment (Germany)
* Republic Pictures (majority owned by Paramount)
* Roadshow Entertainment (Australia)
* Samsung Entertainment Group
* Simitar (Beast) (200+ titles in 1997)
* Sierra Vista Entertainment (Innovacom)
* Silver Screen
* Sony Music Entertainment/Sony Wonder
* Tai Seng
* Toshiba EMI
* 20th Century Fox (unofficial, 36 titles beginning in 1998, including
Star Wars SE)
* United American
* Universal Studios Home Video (Matsushita) (60+ titles by June 1998)
* VCA Labs (adult)
* Victor Entertainment (JVC)
* Vivid Entertainment (adult)
* Warner Home Video (Toshiba partner) (125 titles in 1997)
* Warner Bros. Records (Toshiba partner)
A list of studio addresses is available at
* Alliance Semiconductor: DVD-accelerated video controller chips
* Apple: DVD-ROM drives, DVD-ROM-equipped computers, software drivers,
playback hardware and software (QuickTime)
* AST: DVD-ROM-equipped computers (with MMX-based playback software)
* ATI Technologies: DVD-accelerated video audio/video cards
* Axis Communications: DVD-ROM servers
* C-Cube: DVD encoder and decoder chips
* CEI: DVD playback hardware and software
* Chromatic Research: DVD decoder and playback chips
* Cirrus Logic: DVD-accelerated video controller chips
* Compaq: DVD-ROM-equipped computers
* Creative Technology: DVD-accelerated audio/video cards, DVD upgrade kit
* Diamond Multimedia: DVD playback hardware (Toshiba drive) (upgrade kit)
* Digital: DVD software playback (for Alpha workstations), DVD encoder
* DynaTek: DVD upgrade kit
* E4 (Elecede): DVD playback hardware
* Elektroson: DVD-recordable software (top.GEAR)
* ESS Technology: playback chipset, player reference design
* Fujitsu: DVD-ROM-equipped computers
* Gatway: DVD-ROM-equipped computers
* Harman Int.: DVD jukebox
* Hitachi: DVD-ROM drives, decoder chips
* Hi-Val: DVD playback hardware (upgrade kit)
* Hyundai: DVD decoder chips
* IBM: DVD-ROM-equipped computers, decoder chips
* Innovacom: DVD encoder and decoder systems
* Intel: DVD playback hardware (MMX) and software
* JVC: DVD-ROM drives
* Kasan: decoder hardware
* LG Electronics: DVD-ROM drives
* LSI: DVD decoder chips and playback cards
* LuxSonor: DVD playback chips
* Margi: DVD decoder card for notebook PCs
* Matrox: DVD-accelerated video cards
* Matsushita (Panasonic): DVD-ROM drives, upgrade kits, DVD/Web
* Mediamatics: DVD playback software and hardware
* Medianix: Dolby Digital decoder hardware with Spatializer 3D audio
* Microsoft: DVD drivers and playback software (ActiveMovie)
* Mitsubishi: DVD-ROM drives
* Motorola: DVD decoder chips
* Number 9: DVD-accelerated audio/video cards
* NEC: DVD-ROM drives
* NSM: DVD-ROM jukebox
* Oak Technology: DVD playback hardware and software
* Packard Bell: DVD-ROM-equipped computers
* Philips: DVD-ROM drives, decoder chips
* Pioneer: DVD-ROM drives
* Procom: DVD-ROM jukebox
* Quadrant International: DVD-Video navgation software
* S3: DVD-accelerated video controller chips
* Samsung: DVD-ROM drives and DVD-ROM-equipped computers
* SGS-Thomson: DVD playback hardware (w/Microsoft)
* SICAN: DVD decoder chips
* Software Architects: DVD-recordable software (w/Elektroson)
* Sony: DVD-ROM drives and DVD-ROM-equipped computers
* STB Systems: DVD playback hardware (upgrade kit)
* TDK: blank DVD-RAM discs
* Toshiba: DVD-ROM drives and DVD-ROM-equipped computers
* Trident Microsystems: DVD decoder chips, DVD-accelerated video
* Truevision: DVD playback software (Microsoft Active Movie 2.0)
* Verbatim Australia (ActiveMedia): DVD playback hardware (upgrade kit)
* Wired: DVD playback hardware and software
* Yamaha: AC-3 decoder chips
* Zoran/CompCore: DVD software and hardware playback, DVD decoder chips
Computer software titles on DVD-ROM:
* 2 Way Media: Launch
* Accolade: Jack Nicklaus 4
* Activision: Spycraft: The Great Game, Muppet Treasure Island
* Byron Preiss/Simon & Schuster: The Timetables of Technology
* Creative Multimedia: Billboard Music Guide, Blockbuster Entertainment
Guide to Movies and Video
* Digital Directory Assistance: PhoneDisc PowerFinder USA One
* Discovery Channel
* Discovery Communications: Leopard Son/Animal Planet
* Electronic Arts: Wing Commander IV
* genX Software: Dead-Moon Junction
* Graphix Zone
* Grolier: Multimedia Encyclopedia
* GT Entertainment: Forrest Gump
* Interactual Technologies: Star Trek VideoSaver
* IVS: The Union Catalogue of Belgian Research Libraries
* Japan Travel Bureau: DVD-Web product
* The Learning Company (SoftKey): Digital Library, The Genius of Edison,
Battles of the World
* Mechadeus: The Daedalus Encounter
* Multicom: HomeDepot's Home Improvement 1-2-3; Warren Miller's Ski World
'97; Exploring National Parks; Great Chefs, Great Cities; Better Homes
and Gardens Cool Crafts
* Pro CD: Select Phone
* ReadySoft: Dragon's Lair
* Sega: 4 game/instruction titles to be released in early 1997
* Sumeria: Vanishing Wonders of the Sea, Wild Africa
* SuperZero: adult DVD-Video
* TerraGlyph Interactive Studios: Buster and the Beanstalk (Tiny Toons)
* Tsunami: Crazy 8's, Silent Steel, Silent Steel II
* Warner Advanced Media
* Westwood Studios: Command & Conquer
* Xiphias: Encyclopedia Electronica
* Zombie VR Studios: Liberty
At last count (in Feb 1997), there were 139 registered Internet domain names
with DVD in them. (Thanks to Robert for this interesting tidbit.)
[6.3] Where can I get more information about DVD?
Here are a few of the top DVD info pages. For more extensive pointers go to
Robert's page, which has all the links you will ever need.
* Robert's DVD Info: <http://www.unik.no/~robert/hifi/dvd/>
* Kilroy's DVD FAQs:
and <http://www.icdia.org/dvdfaq02.html> (oriented toward CD-i)
* Chad Fogg's technical notes: <http://www.mpeg.org/~tristan/MPEG/DVD/>
* DVD-Video Production Guidebook: <http://www.nbdig.com/html/dvdmain.htm>
(very technical and poorly translated from Japanese)
* Quantel Digital Fact Book (digital video info and glossary):
* DVD for not-so-Dummies, from Nimbus <http://www.nimbuscd.com/dvd.htm>
* DVD Primer, from Sonic Solutions
* SPA (IMA) DVD SIG: <http://www.spa.org/dvd> <http://www.ima.org/cp/dvd>
* Tristan's MPEG Pointers and Resources <http://www.mpeg.org>
* Compuserve Multimedia Forum, DVD Section (Go MMFORUM)
* DVD discussion list. Send "subscribe DVD-L <your name>" to
* For details on YUV, RGB, YCrCb, etc., read Charles Poynton's Color FAQ
(or buy his book).
You might also want to take a look at the book DVD Demystified, by the
author of this FAQ. More info at <http://www.videodiscovery.com/dvd>.
[7.1] Unanswered questions
(If you know the answer to any of these, please speak up!)
* Any more layer-switch times that aren't in the list? (1.27)
* Any more discs which require flipping that aren't in the list? (1.21)
* What is the exact format of component Y/R-Y/B-Y video output on DVD
players? YPrPb with Rec. 601 scale factors? What's the interface
standard? SMPTE 253M or Betacam or M-II?
* Are there official designations for 8 cm discs (DVD-1, DVD-2, etc.?)
[7.2] Notation and units
There's an unfortunate confusion of units of measurement in the DVD world.
For example, a single-layer DVD holds 4.7 billion bytes (G bytes), not 4.7
gigabytes (GB). It only holds 4.38 gigabytes. Likewise, a double-sided,
dual-layer DVD holds only 15.90 gigabytes, which is 17 billion bytes.
The problem is that "kilo," "mega," and "giga" generally represent multiples
of 1000 (10^3, 10^6, and 10^9), but when used in the computer world to
measure bytes they generally represent multiples of 1024 (2^10, 2^20, and
Most DVD figures are based on multiples of 1000, in spite of using notation
such as GB and KB/s that traditionally have been based on 1024. The closest
I have been able to get to an unambiguous notation is to use kbps for
thousands of bits/sec, Mbps for millions of bits/sec, KB for 1024 bytes, MB
for 1,048,576 bytes, and GB for 1,073,741,824 bytes.
This FAQ is written and maintained by Jim Taylor. The following people have
contributed to the FAQ (either directly, by posting to alt.video.dvd, or by
me borrowing from their writing :-). Their contributions are deeply
appreciated. Information has also been taken from material distributed at
the April 1996 DVD Forum and May 1997 DVD-R/DVD-RAM Conference.
Robert Lundemo Aas
Robert "Obi" George
Henrik "Leopold" Herranen
This document may be freely redistributed only in its entirety with
authorship notice and acknowledgements intact. No part of it may be sold for
profit or incorporated in a commercial document without the permission of
the copyright holder. Permission is granted for complete electronic copies
to be made available as an archive or mirror service on the condition that
the copy be kept up to date. This document is provided as is without any
express or implied warranty.